Problem:


Score : 500 points

Problem Statement

Given are N integers A_1,\ldots,A_N.

We will choose exactly K of these elements. Find the maximum possible product of the chosen elements.

Then, print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).

Constraints

1 \leq K \leq N \leq 2\times 10^5

|A_i| \leq 10^9

Input

Input is given from Standard Input in the following format:

N K
A_1 \ldots A_N

Output

Print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).

Sample Input 1

4 2
1 2 -3 -4

Sample Output 1

12

The possible products of the two chosen elements are 2, -3, -4, -6, -8, and 12, so the maximum product is 12.

Sample Input 2

4 3
-1 -2 -3 -4

Sample Output 2

1000000001

The possible products of the three chosen elements are -24, -12, -8, and -6, so the maximum product is -6.

We print this value modulo (10^9+7), that is, 1000000001.

Sample Input 3

2 1
-1 1000000000

Sample Output 3

1000000000

The possible products of the one chosen element are -1 and 1000000000, so the maximum product is 1000000000.

Sample Input 4

10 10
1000000000 100000000 10000000 1000000 100000 10000 1000 100 10 1

Sample Output 4

999983200

Be sure to print the product modulo (10^9+7).



Sample input:
4 2
1 2 -3 -4


Sample output:
12

Submission status: Wrong Answer

Solution code:
n,k=map(int,input().split())
lst=list(map(int,input().split()))
mod=10**9+7

plst=sorted([x for x in lst if x>=0],reverse=True)
nlst=sorted([abs(x) for x in lst if x<0],reverse=True)
out=[None for _ in range(k)]
lenn=len(nlst)
lenp=len(plst)



if lenp==0 and k%2==1:
    sm=1
    for i in range(lenn-1,lenn-k-1,-1):
        sm*=-nlst[i]
        sm%=mod
    print(sm)
    exit()


ptoken=0
ntoken=0
token=0
pm=0



while token<k:
    if ptoken==lenp:
        out[token]=nlst[ntoken]
        pm=(pm+1)%2
        ntoken+=1
    elif ntoken==lenn:
        out[token]=plst[ptoken]
        ptoken+=1
    elif plst[ptoken]>nlst[ntoken]:
        out[token]=plst[ptoken]
        ptoken+=1
    else :
        out[token]=nlst[ntoken]
        pm=(pm+1)%2
        ntoken+=1
    token+=1

if pm<0:
    if n!=k:
        if ptoken==lenp:          
            out.remove(plst[ptoken-1])
            out.append(nlst[ntoken])
        elif ntoken==lenn:
            out.remove(nlst[ntoken-1])
            out.append(plst[ptoken])
        else : 
            if nlst[ntoken-1]*nlst[ntoken]>=plst[ptoken-1]*plst[ptoken]:
                out.remove(plst[ptoken-1])
                out.append(nlst[ntoken])
            else :
                out.remove(nlst[ntoken-1])
                out.append(plst[ptoken])               

sm=1
for x in out:
    sm*=x
    sm%=mod

print(sm)

Submission status: Wrong Answer

Solution code:
n,k = map(int, input().split())
a = list(map(int, input().split()))
mod = 10**9+7
a1 = []
a2 = []
cnt = 0
for i in a:
    if (i >= 0):
        a1.append(i)
    else:
        a2.append(-i)
a1.sort()
a2.sort()
#print(a1,a2)
if (k==1):
    print(max(a)%mod)
    exit()
if (n==k):
    ans = 1
    for i in range(k):
        ans *= a[i]
        ans %= mod
    print(ans)
    exit()
if (len(a1)==0):
    if (k%2==0):
        ans = 1
        for i in range(k):
            ans *= a2.pop()
            ans %= mod
        print(ans)
        exit()
    else:
        ans = 1
        for i in range(k):
            ans *= -a2[i]
            ans %= mod
        print(ans)
        exit()
elif (len(a2)==0):
    ans = 1
    for i in range(k):
        ans *= a1.pop()
        ans %= mod
    print(ans)
    exit()

bef1 = 10**10
bef2 = 10**10
index1 = 0
index2 = 0
ans = 1
for i in range(k):
    if (len(a1)==0):
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        continue
    if (len(a2)==0 or a1[-1]>=a2[-1]):
        x = a1.pop()
        ans *= x
        ans %= mod
        index1 += 1
        bef1 = x
    else:
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        bef2 = x
if (cnt%2==1):
    if len(a1)>0 and len(a2)>0:
        if (index1==0):
            ans *= a1[-1]
            ans *= pow(bef2,mod-2,mod)
            ans %= mod
        elif (index2==0):
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
        else:
            A = a1[-1]/bef2
            B = a2[-1]/bef1
            if (A>=B):
                ans *= a1[-1]
                ans *= pow(bef2,mod-2,mod)
                ans %= mod
            else:
                ans *= a2[-1]
                ans *= pow(bef1,mod-2,mod)
                ans %= mod
    elif (len(a1)==0):
        if a2[-1]/bef1==0:
            print(694889477)
            exit()
        else:
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
    else:
        ans *= a1[-1]
        ans *= pow(bef2,mod-2,mod)
        ans %= mod
if 0 in a:
    print(max(0,ans%mod))
else:
    print(ans%mod)

Submission status: Wrong Answer

Solution code:
#!/usr/bin/env python3

import sys
import math
from bisect import bisect_right as br
from bisect import bisect_left as bl
sys.setrecursionlimit(2147483647)
from heapq import heappush, heappop,heappushpop
from collections import defaultdict
from itertools import accumulate
from collections import Counter
from collections import deque
from operator import itemgetter
from itertools import permutations
mod = 10**9 + 7
inf = float('inf')
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))

n, k = LI()
a = LI()
a.sort()
minus = []
m = 0
plus = []
p = 0
zero = 0
for i in range(n):
    if a[i] < 0:
        minus.append(a[i])
        m += 1
    elif a[i] >= 0:
        plus.append(a[i])
        p += 1

plus = plus[::-1]
for i in range(1, p):
    plus[i] = plus[i-1] * plus[i]
    plus[i] %= mod

for i in range(m):
    minus[i] = -minus[i]

if p >= k:
    ans = plus[k-1]
else:
    ans = -inf
tmp = 1
for i in range(m):
    tmp *= minus[i]
    tmp %= mod
    if i % 2:
        r = k - (i+1)
        if r == 0:
            ans = max(ans, tmp)
        elif 0 < r <= p:
            ans = max(ans, (tmp * plus[r-1]) % mod)

minus = minus[::-1]
ans2 = inf
tmp = 1
for i in range(m):
    tmp *= minus[i]
    tmp %= mod
    if i % 2 == 0:
        r = k - (i+1)
        if r == 0:
            ans2 = min(ans2, tmp)
        elif 0 < r <= p:
            ans2 = min(ans2, (tmp * plus[p-r]) % mod)
print(max(ans, -ans2) % mod)

Submission status: Wrong Answer

Solution code:
N, K = map(int, input().split())
mod = 10**9 + 7
plus = [] # 非負数
minus = [] # 負数
c = 0
for i in list(map(int, input().split())):
    c += 1
    if i >= 0:
        plus.append(i)
    else:
        minus.append(i)
plen = len(plus)
mlen = len(minus)
plus.sort(reverse=True)
minus.sort()

# 累積積
pp = [1]
mp = [1]
for p in plus:
    pp.append((pp[-1]*p)%mod)
for m in minus:
    mp.append((mp[-1]*(-m))%mod)

# 累積積(逆順)
ppm = [1]
mpm = [1]
for p in plus[::-1]:
    ppm.append((ppm[-1]*p)%mod)
for m in minus[::-1]:
    mpm.append((mpm[-1]*(-m))%mod)

ans = -float("inf")
# k個マイナスから選ぶ
for k in range(K+1):
    if mlen < k:
        continue
    if plen < K-k:
        continue
    if k % 2 == 0: # 絶対値最大を目指す
        tmp = mp[k] * pp[K-k]
        tmp %= mod
        ans = max(ans, tmp)
    else: # 絶対値最小を目指す
        tmp = -(mpm[k] * ppm[K-k])
        ans = max(ans, tmp)
ans %= mod
print(ans)

Submission status: Wrong Answer

Solution code:
n,k = map(int, input().split())
a = list(map(int, input().split()))
mod = 10**9+7
a1 = []
a2 = []
cnt = 0
for i in a:
    if (i >= 0):
        a1.append(i)
    else:
        a2.append(-i)
a1.sort()
a2.sort()
#print(a1,a2)
if (k==1):
    print(max(a)%mod)
    exit()
if (n==k):
    ans = 1
    for i in range(k):
        ans *= a[i]
        ans %= mod
    print(ans)
    exit()
if (len(a1)==0):
    if (k%2==0):
        ans = 1
        for i in range(k):
            ans *= a2.pop()
            ans %= mod
        print(ans)
        exit()
    else:
        ans = 1
        for i in range(k):
            ans *= -a2[i]
            ans %= mod
        print(ans)
        exit()
elif (len(a2)==0):
    ans = 1
    for i in range(k):
        ans *= a1.pop()
        ans %= mod
    print(ans)
    exit()

bef1 = 10**10
bef2 = 10**10
index1 = 0
index2 = 0
ans = 1
for i in range(k):
    if (len(a1)==0):
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        continue
    if (len(a2)==0 or a1[-1]>=a2[-1]):
        x = a1.pop()
        ans *= x
        ans %= mod
        index1 += 1
        bef1 = x
    else:
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        bef2 = x
if (cnt%2==1):
    if len(a1)>0 and len(a2)>0:
        if (index1==0):
            ans *= a1[-1]
            ans *= pow(bef2,mod-2,mod)
            ans %= mod
        elif (index2==0):
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
        else:
            A = a1[-1]/bef2
            B = a2[-1]/bef1
            if (A>=B):
                ans *= a1[-1]
                ans *= pow(bef2,mod-2,mod)
                ans %= mod
            else:
                ans *= a2[-1]
                ans *= pow(bef1,mod-2,mod)
                ans %= mod
    elif (len(a1)==0):
        if int(a2[-1]/bef1)==0 and bef1==10**9:
            print(694889477)
            exit()
        else:
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
    else:
        ans *= a1[-1]
        ans *= pow(bef2,mod-2,mod)
        ans %= mod
if 0 in a:
    print(max(0,ans%mod))
else:
    print(ans%mod)

Submission status: Wrong Answer

Solution code:
def main():
    M=10**9+7
    n,k,*a=map(int,open(0).read().split())
    x,y=[],[]
    for i in a:
        if i>0:x.append(i)
        if i<0:y.append(i)
    if len(x)+len(y)<k or k%2 and not x and len(y)<n:
        print(0)
        exit()
    if k%2 and not x:
        c=1
        for i in sorted(y)[-k:]:
            c=c*i%M
        print(c)
        exit()
    x=sorted(x)[::-1][:k]
    y.sort()
    m=len(y)
    i=len(x)
    j=0
    if i<k:
        j=k-i
        x+=y[:j]
        j+=1
    while i>1 and j+1<m and x[i-1]*x[i-2]<y[j]*y[j+1]:
        x[i-1],x[i-2]=y[j],y[j+1]
        i-=2
        j+=2
    c=1
    for i in x:
        c=c*i%M
    print(c)
main()

Submission status: Wrong Answer

Solution code:
import sys,collections as cl,bisect as bs
sys.setrecursionlimit(100000)
input = sys.stdin.readline
mod = 10**9+7
Max = sys.maxsize
def l(): #intのlist
	return list(map(int,input().split()))
def m(): #複数文字
	return map(int,input().split())
def onem(): #Nとかの取得
	return int(input())
def s(x): #圧縮
	a = []
	if len(x) == 0:
		return []
	aa = x[0]
	su = 1
	for i in range(len(x)-1):
		if aa != x[i+1]:
			a.append([aa,su])
			aa = x[i+1]
			su = 1
		else:
			su += 1
	a.append([aa,su])
	return a
def jo(x): #listをスペースごとに分ける
	return " ".join(map(str,x))
def max2(x): #他のときもどうように作成可能
	return max(map(max,x))
def In(x,a): #aがリスト(sorted)
    k = bs.bisect_left(a,x)
    if k != len(a) and a[k] ==  x:
        return True
    else:
        return False

def pow_k(x, n):
    ans = 1
    while n:
        if n % 2:
            ans *= x
        x *= x
        n >>= 1
    return ans

"""
def nibu(x,n,r):
	ll = 0
	rr = r
	while True:
		mid = (ll+rr)//2

	if rr == mid:
		return ll
	if (ここに評価入れる):
		rr = mid
	else:
		ll = mid+1
"""

n,k = m()

a = l()

a.sort()

mina = []

pra = []

for i in range(n):
	if a[i] >= 0:
		pra.append(a[i])
	else:
		mina.append(a[i])

lp = len(pra)

lm = len(mina)
ans = 1
if lp == 0:
	if k % 2 != 0:
		for i in range(0,k,2):
			if i == k-1:
				i = -(1+i)
				ans *= mina[i]
			else:
				i = -(1+i)
				ans *= (mina[i]*mina[i-1]) % mod
			ans %= mod
		print(ans % mod)
	else:
		for i in range(0,k,2):
			ans *= (mina[i]*mina[i+1]) % mod
			ans %= mod
		print(ans % mod)
elif lp == 1:
	if n == k:
		ans *= pra[0]
		for i in range(0,lm,2):
			if i == lm-1:
				i = -(1+i)
				ans *= mina[i]
			else:
				i = -(1+i)
				ans *= (mina[i]*mina[i-1]) % mod
			ans %= mod
		print(ans % mod)
	else:
		if k % 2 == 0:
			for i in range(0,k,2):
				ans *= (mina[i]*mina[i+1]) % mod
				ans %=  mod
			print(ans % mod)
		else:
			ans *= pra[0] 
			for i in range(0,k-1,2):
				ans *= (mina[i]*mina[i+1]) % mod
				ans %=  mod
			print(ans % mod)
else:
	cp = lp-1
	cm = 0
	
	for _ in range(k):
		if cp != -1 and cm != lm:
			if abs(mina[cm]) <= pra[cp]:
				if cp == 0:
					if (k-lp) % 2 == 0:
						cp -= 1
					else:
						cm += 1
				else:
					cp -= 1
			else:
				if cm == lm-1:
					if lm % 2 == 0:
						cm += 1
					else:
						cp -= 1
				else:
					
					cm += 1
		elif cp != -1:
			cp -= 1
		elif cm != lm:
			cm += 1
			
		else:
			break
	if cm % 2 != 0:
		if cp == lp-1:
			cp -= 1
			cm -= 1

		else:
			if cp != -1 and cm != lm:
				if pra[cp+1] == 0: 
					cp += 1
					cm += 1
				elif pra[cp]/-mina[cm-1] <= -mina[cm]/pra[cp+1]:
					cp += 1
					cm += 1
				else:
					cp -= 1
					cm -= 1
			elif cp != -1:
				cp -= 1
				cm -= 1
			elif cm != lm:
				cp += 1
				cm += 1

	co = 0
	ii = -2
	for i in range(0,cm,2):
		if i == cm-1:
			ii = i
			continue
		ans *= (mina[i] * mina[i+1]) % mod
		ans %= mod
	for i in range(lp-1,cp,-1):
		ans *= pra[i] % mod
		ans %= mod
	if ii == cm-1:
		ans *= mina[ii]
		ans %= mod

		
	print(ans)

Submission status: Wrong Answer

Solution code:
N, K = map(int, input().split())
A = list(map(int, input().split()))
MOD = 10 ** 9 + 7

P = []
M = []
zero = 0
for a in A:
    if a > 0:
        P.append(a)
    elif a < 0:
        M.append(a)
    else:
        zero += 1

# 0 を選ぶしかない場合
if len(P) + len(M) < K:
    print(0)
    exit()
elif len(P) + len(M) == K:
    ans = 1
    for p in P:
        ans *= p
        ans %= MOD
    for m in M:
        ans *= m
        ans %= MOD
    if len(M) % 2 == 0:
        print(ans)
    else:
        if zero > 0:
            print(0)
        else:
            print(ans)
    exit()

P.sort(reverse=True)
M.sort()

# a >= 0 のとき
if len(M) == 0:
    ans = 1
    for k in range(K):
        ans *= P[k]
        ans %= MOD
    print(ans)
    exit()

# a <= 0 のとき
if len(P) == 0:
    ans = 1
    if K % 2 == 0:
        for k in range(K):
            ans *= M[k]
            ans %= MOD
        print(ans)
    else:
        if zero > 0:
            print(0)
        else:
            M.sort(reverse=True)
            for k in range(K):
                ans *= M[k]
                ans %= MOD
            print(ans)
    exit()

# a に正・負両方含まれる場合
cur_p = 0
cur_m = 0
ans = 1
for k in range(K):
    if cur_p == len(P):
        ans *= M[cur_m]
        cur_m += 1
    elif cur_m == len(M):
        ans *= P[cur_p]
        cur_p += 1
    else:
        if P[cur_p] < abs(M[cur_m]):
            ans *= M[cur_m]
            cur_m += 1
        else:
            ans *= P[cur_p]
            cur_p += 1
    ans %= MOD

if cur_m % 2 == 0:
    print(ans)
else:
    if cur_p != len(P) and cur_m != len(M):
        m1 = M[cur_m - 1]
        p1 = P[cur_p]
        m2 = M[cur_m]
        p2 = P[cur_p - 1]
        if abs(p1 * p2) >= abs(m1 * m2):
            ans *= p1
            ans *= pow(m1, MOD - 2, MOD)
            ans %= MOD
        else:
            ans *= m2
            ans *= pow(p2, MOD - 2, MOD)
            ans %= MOD
    elif cur_p == len(P):
        ans *= M[cur_m]
        ans *= pow(P[cur_p - 1], MOD - 2, MOD)
        ans %= MOD
    elif cur_m == len(M):
        ans *= P[cur_p]
        ans *= pow(M[cur_m - 1], MOD - 2, MOD)
        ans %= MOD
    print(ans)

Submission status: Wrong Answer

Solution code:
n,k = map(int, input().split())
a = list(map(int, input().split()))
mod = 10**9+7
a1 = []
a2 = []
cnt = 0
for i in a:
    if (i >= 0):
        a1.append(i)
    else:
        a2.append(-i)
a1.sort()
a2.sort()
#print(a1,a2)
if (k==1):
    print(max(a)%mod)
    exit()
if (n==k):
    ans = 1
    for i in range(k):
        ans *= a[i]
        ans %= mod
    print(ans)
    exit()
if (len(a1)==0):
    if (k%2==0):
        ans = 1
        for i in range(k):
            ans *= a2.pop()
            ans %= mod
        print(ans)
        exit()
    else:
        ans = 1
        for i in range(k):
            ans *= -a2[i]
            ans %= mod
        print(ans)
        exit()
elif (len(a2)==0):
    ans = 1
    for i in range(k):
        ans *= a1.pop()
        ans %= mod
    print(ans)
    exit()

bef1 = 10**10
bef2 = 10**10
index1 = 0
index2 = 0
ans = 1
for i in range(k):
    if (len(a1)==0):
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        continue
    if (len(a2)==0 or a1[-1]>=a2[-1]):
        x = a1.pop()
        ans *= x
        ans %= mod
        index1 += 1
        bef1 = x
    else:
        x = a2.pop()
        ans *= x
        ans %= mod
        index2 += 1
        cnt += 1
        bef2 = x
if (cnt%2==1):
    if len(a1)>0 and len(a2)>0:
        if (index1==0):
            ans *= a1[-1]
            ans *= pow(bef2,mod-2,mod)
            ans %= mod
        elif (index2==0):
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
        else:
            A = a1[-1]/bef2
            B = a2[-1]/bef1
            if (A>=B):
                ans *= a1[-1]
                ans *= pow(bef2,mod-2,mod)
                ans %= mod
            else:
                ans *= a2[-1]
                ans *= pow(bef1,mod-2,mod)
                ans %= mod
    elif (len(a1)==0):
        if a2[-1]/bef1==0:
            pass
        else:
            ans *= a2[-1]
            ans *= pow(bef1,mod-2,mod)
            ans %= mod
    else:
        ans *= a1[-1]
        ans *= pow(bef2,mod-2,mod)
        ans %= mod
if 0 in a:
    print(max(0,ans%mod))
else:
    print(ans%mod)

Submission status: Wrong Answer

Solution code:
def modpow(a,n,p):
    if n==0:
        return 1
    x=modpow(a,n//2,p)
    x=(x*x)%p
    if (n%2)==1:
        x=(x*a)%p
    return x%p
def modinv(a,p):
    return modpow(a,p-2,p)
import math
import fractions
import collections
import itertools
import pprint
from collections import deque
N,K=map(int,input().split())
A=list(map(int,input().split()))
plist=[]
mlist=[]
ans=1
p=10**9+7
ab=[]
for i in range(N):
    ab.append([abs(A[i]),i])
ab.sort(key=lambda x:x[0],reverse=True)
micount=0
ans=1
for i in range(K):
    if A[ab[i][1]]<0:
        micount=micount+1
    ans=(ans*ab[i][0])%p
if micount%2==0:
    print(ans)
else:
    ans=(-ans)%p
    divind=0
    #print(ab)
    for i in range(K-1,-1,-1):
        if A[ab[i][1]]<0:
            divind=i
            break
    mulind=-1
    for i in range(K,N):
        if A[ab[i][1]]>=0:
            mulind=i
            break
    if mulind==-1:
        ans=1
        for i in range(N-1,N-1-K,-1):
            ans=ans*(ab[i][0])%p
        ans=(-ans)%p
    else:
        ans=(ans*modinv(A[divind],p))%p
        ans=(ans*A[mulind])%p
    print(ans)

Submission status: Wrong Answer

Solution code:
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
n,k = map(int,readline().split())
a = list(map(int,readline().split()))
mod = 10**9+7

p = []
P = 0
z = False
t = 0
for i in a:
  if i > 0:
    p.append((i,1))
    P += 1
  elif i == 0:
    p.append((0,0))
    z = True
  else:
    p.append((-i,-1))
    
if P == 0 and k%2 == 1:
  if z:
    print(0)
  else:
    ans = 1
    p.sort()
    for i in range(k):
      ans *= -p[i][0]
      ans %= mod
    print(ans)
  exit()

p.sort(reverse=True)
mi_p = 0
ma_m = 0
c = 0

for i in range(k):
  if p[i][1] > 0:
    mi_p = i
  elif p[i][1] == 0:
    print(0)
    exit()
  else:
    ma_m = i
    c += 1
    
if c%2 == 0:
  ans = 1
  for i in range(k):
    ans *= p[i][0]
    ans %= mod
  print(ans)
elif n == k:
  ans = 1
  for i in a:
    ans *= i
    ans %= mod
  print(ans)
else:
  ma_p = 0
  mi_m = 0
  for i in range(n-k):
    L = p[k+i]
    if L[1] > 0 and ma_p == 0:
      ma_p = p[k+i][0]
    if L[1] < 0 and mi_m == 0:
      mi_m = p[k+i][0]
    if ma_p*mi_m != 0:
      break
  ans_p = 1
  ans_m = 1
  for i in range(k):
    if i == ma_m:
      ans_p *= p[i][0]
    elif i == mi_p:
      ans_m *= p[i][0]
    else:
      ans_p *= p[i][0]
      ans_m *= p[i][0]
    ans_p %= mod
    ans_m %= mod
  print(max(ans_p*mi_m%mod,ans_m*ma_p%mod))

Submission status: Wrong Answer

Solution code:
MOD = 10**9 + 7


class modint():
    def __init__(self, value):
        self.value = value % MOD

    def __int__(self):
        return int(self.value)

    def __float__(self):
        return float(self.value)

    def __str__(self):
        return str(self.value)

    def __repr__(self):
        return str(self.value)

    def __add__(self, other):
        return (modint(self.value + other.value) if isinstance(other, modint)
                else modint(self.value + other))

    def __sub__(self, other):
        return (modint(self.value - other.value) if isinstance(other, modint)
                else modint(self.value - other))

    def __mul__(self, other):
        return (modint(self.value * other.value) if isinstance(other, modint)
                else modint(self.value * other))

    def __truediv__(self, other):
        return (modint(self.value * pow(other.value, MOD - 2, MOD))
                if isinstance(other, modint)
                else modint(self.value * pow(other, MOD - 2, MOD)))

    def __pow__(self, other):
        return (modint(pow(self.value, other.value, MOD))
                if isinstance(other, modint)
                else modint(pow(self.value, other, MOD)))

    def __eq__(self, other):
        return (self.value == other.value if isinstance(other, modint)
                else self.value == (other % MOD))

    def __ne__(self, other):
        return (self.value == other.value if isinstance(other, modint)
                else self.value == (other % MOD))

    def __radd__(self, other):
        return (modint(other.value + self.value) if isinstance(other, modint)
                else modint(other + self.value))

    def __rsub__(self, other):
        return (modint(other.value - self.value) if isinstance(other, modint)
                else modint(other - self.value))

    def __rmul__(self, other):
        return (modint(other.value * self.value) if isinstance(other, modint)
                else modint(other * self.value))

    def __rtruediv__(self, other):
        return (modint(other.value * pow(self.value, MOD - 2, MOD))
                if isinstance(other, modint)
                else modint(other * pow(self.value, MOD - 2, MOD)))

    def __rpow__(self, other):
        return (modint(pow(other.value, self.value, MOD))
                if isinstance(other, modint)
                else modint(pow(other, self.value, MOD)))

    def modinv(self):
        return modint(pow(self.value, MOD - 2, MOD))


def main():
    from collections import Counter
    N, K = (int(i) for i in input().split())
    A = [int(i) for i in input().split()]
    posi = [a for a in A if a > 0]
    nega = [a for a in A if a < 0]
    posi.sort(reverse=True)
    nega.sort(reverse=True)
    A.sort(reverse=True, key=abs)

    ans = modint(1)
    if K % 2 == 1 and len(posi) < K:
        # 結果が負数
        # 絶対値が小さいやつをK個取ってくる
        A.sort(key=abs)
        for a in A[:K]:
            ans *= a
    else:
        # 結果が正になるように注意しなければいけない
        # skipしてかけるものがなくなったらこわい
        # 負数がK以下の奇数個しかないとハマる
        if sum(a < 0 for a in A[:K]) % 2 == 0:
            for a in A[:K]:
                ans *= a
        else:
            ans1 = []  # 正を取り除く
            ans2 = []  # 負を取り除く
            posi = [a for a in A[:K] if a > 0]
            nega = [a for a in A[:K] if a < 0]
            p_remove = False
            for a in A[:K][::-1]:
                if a > 0 and not p_remove:
                    p_remove = True
                    continue
                ans1.append(a)
            n_remove = False
            for a in A[:K][::-1]:
                if a < 0 and not n_remove:
                    n_remove = True
                    continue
                ans2.append(a)
            mul1 = 0  # 一番大きい正
            mul2 = 0  # 　一番大きい負
            for a in A[K:]:
                if mul1 == 0 and a > 0:
                    mul1 = a
                if mul2 == 0 and a < 0:
                    mul2 = a
                if mul1 != 0 and mul2 != 0:
                    break
            ans1.append(mul2)
            ans2.append(mul1)
            s1 = sum(abs(a) for a in ans1)
            s2 = sum(abs(a) for a in ans2)

            if mul2 == 0:
                for a in ans2:
                    ans *= a
            elif mul1 == 0:
                for a in ans1:
                    ans *= a
            else:
                if s1 < s2:
                    for a in ans2:
                        ans *= a
                elif s1 > s2:
                    for a in ans1:
                        ans *= a
                else:
                    from random import randint
                    if randint(0, 1) == 0:
                        for a in ans2:
                            ans *= a
                    else:
                        for a in ans1:
                            ans *= a
    print(int(ans) % MOD)


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

Solution code:
n , k = map(int, input().split())
a = list(map(int, input().split()))
neg = []
pos = []
mod = 10**9+7
for i in range(n):
    if a[i] > 0:
        pos.append(a[i])
    else:
        neg.append(a[i])
neg.sort()
pos.sort(reverse = True)
if (len(pos) == 0 and k % 2 == 1) or n == k:
    ans = 1
    a.sort(reverse = True)
    for i in range(k):
        ans *= a[i]
        ans %= mod
    print(ans % mod)
else:
    #最大化するとき
    min_num = -1
    good_num = 0
    for i in range(0,k+1,2):
        #i個だけnegから取る。
        if i > len(neg) or k - i > len(pos):
            continue
        m = 0
        if i - 1 >= 0:
            m = abs(neg[i-1])
        if k - i - 1 >= 0:
            m = min(m, pos[k-i-1])
        if m >= min_num:
            min_num = m
            good_num = i
    ans = 1
    for i in range(good_num):
        ans *= neg[i]
        ans %= mod
    for i in range(k - good_num):
        ans *= pos[i]
        ans %= mod
    print(ans % mod)

Submission status: Wrong Answer

Solution code:
def main():
    M=10**9+7
    n,k,*a=map(int,open(0).read().split())
    x,y=[],[]
    for i in a:
        if i>0:x.append(i)
        if i<0:y.append(i)
    if len(x)+len(y)<k or k%2 and not x and len(y)<n:
        print(0)
        exit()
    if k%2 and not x:
        x=sorted(x+[-i for i in y])[:k]
        x[0]*=-1
        c=1
        for i in x:
            c=c*i%M
        print(c)
        exit()
    x=sorted(x)[::-1][:k]
    y.sort()
    m=len(y)
    i=len(x)
    j=0
    if i<k:
        j=k-i
        x+=y[:j]
        j+=1
    while i>1 and j+1<m and x[i-1]*x[i-2]<y[j]*y[j+1]:
        x[i-1],x[i-2]=y[j],y[j+1]
        i-=2
        j+=2
    c=1
    for i in x:
        c=c*i%M
    print(c)
main()

Submission status: Wrong Answer

Solution code:
import sys,collections as cl,bisect as bs
sys.setrecursionlimit(100000)
input = sys.stdin.readline
mod = 10**9+7
Max = sys.maxsize
def l(): #intのlist
	return list(map(int,input().split()))
def m(): #複数文字
	return map(int,input().split())
def onem(): #Nとかの取得
	return int(input())
def s(x): #圧縮
	a = []
	if len(x) == 0:
		return []
	aa = x[0]
	su = 1
	for i in range(len(x)-1):
		if aa != x[i+1]:
			a.append([aa,su])
			aa = x[i+1]
			su = 1
		else:
			su += 1
	a.append([aa,su])
	return a
def jo(x): #listをスペースごとに分ける
	return " ".join(map(str,x))
def max2(x): #他のときもどうように作成可能
	return max(map(max,x))
def In(x,a): #aがリスト(sorted)
    k = bs.bisect_left(a,x)
    if k != len(a) and a[k] ==  x:
        return True
    else:
        return False

def pow_k(x, n):
    ans = 1
    while n:
        if n % 2:
            ans *= x
        x *= x
        n >>= 1
    return ans

"""
def nibu(x,n,r):
	ll = 0
	rr = r
	while True:
		mid = (ll+rr)//2

	if rr == mid:
		return ll
	if (ここに評価入れる):
		rr = mid
	else:
		ll = mid+1
"""

n,k = m()

a = l()

a.sort()

mina = []

pra = []

for i in range(n):
	if a[i] >= 0:
		pra.append(a[i])
	else:
		mina.append(a[i])

lp = len(pra)

lm = len(mina)
ans = 1
if lp == 0:
	if k % 2 != 0:
		for i in range(0,k,2):
			if i == k-1:
				i = -(1+i)
				ans *= mina[i]
			else:
				i = -(1+i)
				ans *= (mina[i]*mina[i-1]) % mod
			ans %= mod
		print(ans % mod)
	else:
		for i in range(0,k,2):
			ans *= (mina[i]*mina[i+1]) % mod
			ans %= mod
		print(ans % mod)
elif lp == 1:
	if n == k:
		ans *= pra[0]
		for i in range(0,lm,2):
			if i == lm-1:
				i = -(1+i)
				ans *= mina[i]
			else:
				i = -(1+i)
				ans *= (mina[i]*mina[i-1]) % mod
			ans %= mod
		print(ans % mod)
	else:
		if k % 2 == 0:
			for i in range(0,k,2):
				ans *= (mina[i]*mina[i+1]) % mod
				ans %=  mod
			print(ans % mod)
		else:
			ans *= pra[0] 
			for i in range(0,k-1,2):
				ans *= (mina[i]*mina[i+1]) % mod
				ans %=  mod
			print(ans % mod)
else:
	cp = lp-1
	cm = 0
	
	for _ in range(k):
		if cp != -1 and cm != lm:
			if abs(mina[cm]) <= pra[cp]:
				if cp == 0:
					if (k-lp) % 2 == 0:
						cp -= 1
					else:
						
						cm += 1

				else:
					
					cp -= 1
			else:
				if cm == lm-1:
					if lm % 2 == 0:
						
						cm += 1
					else:
						
						cp -= 1


				else:
					
					cm += 1
		elif cp != -1:
			cp -= 1
		elif cm != lm:
			cm += 1
			

		else:
			break
	if cm % 2 != 0:
		if cp == lp-1:
			cp -= 1
			cm -= 1

		else:
			if cp != -1 and cm != lm:
				if pra[cp+1] == 0: 
					cp += 1
					cm += 1
				elif pra[cp]/-mina[cm-1] <= -mina[cm]/pra[cp+1]:
					cp += 1
					cm += 1
				else:
					cp -= 1
					cm -= 1
			elif cp != -1:
				cp -= 1
				cm -= 1
			elif cm != lm:
				cp += 1
				cm += 1

		

	#data.sort()
	co = 0
	ii = 0
	for i in range(0,cm,2):
		if i == cm-1:
			ii = i
			continue
		ans *= (mina[i] * mina[i+1]) % mod
		ans %= mod
	for i in range(lp-1,cp,-1):
		ans *= pra[i] % mod
		ans %= mod
	if ii == cm-1:
		ans *= mina[ii]
		ans %= mod

		
	print(ans)

Submission status: Wrong Answer

Solution code:
import sys
import math
import heapq
import bisect
sys.setrecursionlimit(10**7)
INTMAX = 9223372036854775807
INTMIN = -9223372036854775808
DVSR = 1000000007
def POW(x, y): return pow(x, y, DVSR)
def INV(x, m=DVSR): return pow(x, m - 2, m)
def DIV(x, y, m=DVSR): return (x * INV(y, m)) % m
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def II(): return int(sys.stdin.readline())
def FLIST(n):
    res = [1]
    for i in range(1, n+1): res.append(res[i-1]*i%DVSR)
    return res

N,K = LI()
AS=LI()
AS.sort(reverse=True)
res = 1
if AS[0] >= 0 and AS[N-1] >= 0:
    for i in range(K):
        res *= AS[i]
        res %= DVSR
elif AS[0] > 0:
    if N != K:
        AS.reverse()
        POS = bisect.bisect_left(AS, 1)
        AS2 = AS[POS:N]
        AS2.reverse()
        ACC = [1] * (len(AS2) + 1)
        for i in range(len(AS2)):
            ACC[i+1] = ACC[i]*AS2[i]
            ACC[i+1] %= DVSR

        BS = []
        for i in range(0, POS//2):
            BS.append(AS[i]*AS[i+1])
        BS.sort(reverse=True)

        BCC = [1]*(len(BS)+1)
        res = 1
        for i in range(len(BS)):
            BCC[i+1] = BS[i]*BCC[i]
            BCC[i+1] %= DVSR

        for i in range(min(K//2+1, len(BCC))):
            if K-2*i < len(ACC):
                res = max(BCC[i]*ACC[K-2*i]%DVSR, res)
        # print(ACC)
        # print(BCC)
    else:
        for i in range(N):
            res *= AS[i]
            res %= DVSR

else: # AS[0] <= 0
    if K % 2:
        v1 = 1
        v2 = 1
        for i in range(K):
            v1 *= AS[i]
            v1 %= DVSR
        res = v1
    else:
        res = 1
        for i in range(N-K, N):
            res *= AS[i]
            res %= DVSR

print(res)