Problem p02616 (python)

Fixed submission:
from math import log2
from itertools import accumulate

epsilon = 10 ** -5

MOD = 10 ** 9 + 7

N, K = map(int, input().split())
As = list(map(int, input().split()))

negs = []
poss = []
for A in As:
    if A > 0:
        poss.append(A)
    elif A < 0:
        negs.append(-A)

poss.sort(reverse = True)
negs.sort(reverse = True)

if len(poss) + len(negs) < K:
    print(0)
    exit()

if len(poss) == 0:
    if N > len(negs):
        if K % 2 == 1:
            print(0)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    else:
        if K % 2 == 1:
            ans = 1
            for n in negs[-K:]:
                ans *= n
                ans %= MOD
            print(-ans%MOD)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    exit()

if K == N:
    ans = 1
    for A in As:
        ans *= A
        ans %= MOD
    print(ans)
    exit()


def mulmod(a, b):
    return a * b % MOD

logs_poss = [0.0] + [log2(p) for p in poss] 
logs_poss_csum = list(accumulate(logs_poss))

poss_mod_csum = [1] + list(accumulate(poss, mulmod))

logs_negs = [0.0] + [log2(n) for n in negs] 
logs_negs_csum = list(accumulate(logs_negs))

negs_mod_csum = [1] + list(accumulate(negs, mulmod))

max_log = -1
for minus in range(0, K+1, 2):
    plus = K - minus
    if plus <= len(poss) and minus <= len(negs):
        if max_log + epsilon < logs_poss_csum[plus] + logs_negs_csum[minus]:
            max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
            max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
        elif max_log <= logs_poss_csum[plus] + logs_negs_csum[minus]:
            mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
            if mod > max_mod:
                max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
                max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD

print(max_mod)

Buggy submission (verdict: Runtime Error):
from math import log2
from itertools import accumulate

epsilon = 10 ** -5

MOD = 10 ** 9 + 7

N, K = map(int, input().split())
As = list(map(int, input().split()))

negs = []
poss = []
for A in As:
    if A > 0:
        poss.append(A)
    elif A < 0:
        negs.append(-A)

poss.sort(reverse = True)
negs.sort(reverse = True)

if len(poss) + len(negs) < K:
    print(0)
    exit()

if len(poss) == 0:
    if N > len(negs):
        if K % 2 == 1:
            print(0)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    else:
        if K % 2 == 1:
            ans = 1
            for n in negs[-K:]:
                ans *= n
                ans %= MOD
            print(-ans%MOD)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    exit()

if K == N:
    ans = 1
    for A in As:
        ans *= A
        ans %= MOD
    print(ans)



def mulmod(a, b):
    return a * b % MOD

logs_poss = [0.0] + [log2(p) for p in poss] 
logs_poss_csum = list(accumulate(logs_poss))

poss_mod_csum = [1] + list(accumulate(poss, mulmod))

logs_negs = [0.0] + [log2(n) for n in negs] 
logs_negs_csum = list(accumulate(logs_negs))

negs_mod_csum = [1] + list(accumulate(negs, mulmod))

max_log = -1
for minus in range(0, K+1, 2):
    plus = K - minus
    if plus <= len(poss) and minus <= len(negs):
        if max_log + epsilon < logs_poss_csum[plus] + logs_negs_csum[minus]:
            max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
            max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
        elif max_log <= logs_poss_csum[plus] + logs_negs_csum[minus]:
            mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
            if mod > max_mod:
                max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
                max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD

print(max_mod)

Buggy submission (verdict: Runtime Error):
from math import log2
from itertools import accumulate

epsilon = 10 ** -5

MOD = 10 ** 9 + 7

N, K = map(int, input().split())
As = list(map(int, input().split()))

negs = []
poss = []
for A in As:
    if A > 0:
        poss.append(A)
    elif A < 0:
        negs.append(-A)

poss.sort(reverse = True)
negs.sort(reverse = True)

if len(poss) + len(negs) < K:
    print(0)
    exit()

if len(poss) == 0:
    if N > len(negs):
        if K % 2 == 1:
            print(0)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    else:
        if K % 2 == 1:
            ans = 1
            for n in negs[-K:]:
                ans *= n
                ans %= MOD
            print(-ans%MOD)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    exit()

def mulmod(a, b):
    return a * b % MOD

logs_poss = [0.0] + [log2(p) for p in poss] 
logs_poss_csum = list(accumulate(logs_poss))

poss_mod_csum = [1] + list(accumulate(poss, mulmod))

logs_negs = [0.0] + [log2(n) for n in negs] 
logs_negs_csum = list(accumulate(logs_negs))

negs_mod_csum = [1] + list(accumulate(negs, mulmod))

max_log = -1
for minus in range(0, K+1, 2):
    plus = K - minus
    if plus <= len(poss) and minus <= len(negs):
        if max_log + epsilon < logs_poss_csum[plus] + logs_negs_csum[minus]:
            max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
            max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
        elif max_log <= logs_poss_csum[plus] + logs_negs_csum[minus]:
            mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD
            if mod > max_mod:
                max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
                max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD

print(max_mod)

Buggy submission (verdict: Runtime Error):
from math import log2
from itertools import accumulate

MOD = 10 ** 9 + 7

N, K = map(int, input().split())
As = list(map(int, input().split()))

negs = []
poss = []
for A in As:
    if A > 0:
        poss.append(A)
    elif A < 0:
        negs.append(-A)

poss.sort(reverse = True)
negs.sort(reverse = True)

if len(poss) + len(negs) < K:
    print(0)
    exit()

if len(poss) == 0:
    if N > len(negs):
        if K % 2 == 1:
            print(0)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    else:
        if K % 2 == 1:
            ans = 1
            for n in negs[-K:]:
                ans *= n
                ans %= MOD
            print(-ans%MOD)
        else:
            ans = 1
            for n in negs[:K]:
                ans *= n
                ans %= MOD
            print(ans)
    exit()

def mulmod(a, b):
    return a * b % MOD

logs_poss = [0.0] + [log2(p) for p in poss] 
logs_poss_csum = list(accumulate(logs_poss))

poss_mod_csum = [1] + list(accumulate(poss, mulmod))

logs_negs = [0.0] + [log2(n) for n in negs] 
logs_negs_csum = list(accumulate(logs_negs))

negs_mod_csum = [1] + list(accumulate(negs, mulmod))

max_log = -1
for minus in range(0, K+1, 2):
    plus = K - minus
    if plus <= len(poss) and minus <= len(negs):
        if max_log < logs_poss_csum[plus] + logs_negs_csum[minus]:
            max_log = logs_poss_csum[plus] + logs_negs_csum[minus]
            max_mod = poss_mod_csum[plus] * negs_mod_csum[minus] % MOD

print(max_mod)