Problem:


Score : 400 points

Problem Statement

Consider a grid with H rows and W columns of squares. Let (r, c) denote the square at the r-th row from the top and the c-th column from the left.
Each square is painted black or white.

The grid is said to be good if and only if the following condition is satisfied:

From (1, 1), we can reach (H, W) by moving one square right or down repeatedly, while always being on a white square.

Note that (1, 1) and (H, W) must be white if the grid is good.

Your task is to make the grid good by repeating the operation below. Find the minimum number of operations needed to complete the task. It can be proved that you can always complete the task in a finite number of operations.

Choose four integers r_0, c_0, r_1, c_1(1 \leq r_0 \leq r_1 \leq H, 1 \leq c_0 \leq c_1 \leq W). For each pair r, c (r_0 \leq r \leq r_1, c_0 \leq c \leq c_1), invert the color of (r, c) - that is, from white to black and vice versa.

Constraints

2 \leq H, W \leq 100

Input

Input is given from Standard Input in the following format:

H W
s_{11} s_{12} \cdots s_{1W}
s_{21} s_{22} \cdots s_{2W}
 \vdots
s_{H1} s_{H2} \cdots s_{HW}

Here s_{rc} represents the color of (r, c) - # stands for black, and . stands for white.

Output

Print the minimum number of operations needed.

Sample Input 1

3 3
.##
.#.
##.

Sample Output 1

1

Do the operation with (r_0, c_0, r_1, c_1) = (2, 2, 2, 2) to change just the color of (2, 2), and we are done.

Sample Input 2

2 2
#.
.#

Sample Output 2

2

Sample Input 3

4 4
..##
#...
###.
###.

Sample Output 3

0

No operation may be needed.

Sample Input 4

5 5
.#.#.
#.#.#
.#.#.
#.#.#
.#.#.

Sample Output 4

4



Sample input:
3 3
.##
.#.
##.


Sample output:
1

Submission status: Wrong Answer

Solution code:

from collections import defaultdict as dd

def func():
    return float('inf')
def solve(M, H, W):
    dic = dd(func)
    for i in range(h-1, -1, -1):
        for j in range(w-1, -1, -1):
            dic[(i, j)] = min(dic[(i+1, j)], dic[(i, j+1)])
            if dic[(i, j)] == float('inf'):
                dic[(i, j)] = 0
            if M[i][j] == '#':
                dic[(i, j)]+=1

    print(dic[(0, 0)])
            
h, w = map(int, input().split())

M = []
for i in range(h):
    arr = list(input())
    M.append(arr)

solve(M, h, w)

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 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
"""


H,W = m()

po = [list(input()) for i in range(H)]

aaa = [[[mod,0] for i in range(W)] for j in range(H)]
aa = [[[mod,0] for i in range(W)] for j in range(H)]

if po[0][0] == "#":
    aaa[0][0] = [1,3]
else:
    aaa[0][0] = [0,0]

for i in range(H):
    if i == 0:
        for j in range(1,W):
            if po[i][j] == "#":
                if aaa[i][j-1][1] == 0:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1)
                    aaa[i][j][1] = 3
                elif aaa[i][j-1][1] == 1 or aaa[i][j-1][1] == 3:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0])
                    aaa[i][j][1] = 1
            else:
                aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0])

    else:
        for j in range(W):
            if j == 0:
                if po[i][j] == "#":
                    if aaa[i-1][j][1] == 0:
                        aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0]+1)
                        aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 3 or aaa[i-1][j][1] == 2:
                        aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0])
                        aaa[i][j][1] = 2
                else:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0])
            else:
                if po[i][j] == "#":
                    if aaa[i-1][j][1] == 0 or aaa[i-1][j][1] == 1:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 2:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 3:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                else:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])

if po[0][0] == ".":
    aa[0][0] = [1,3]
else:
    aa[0][0] = [1,0]

for i in range(H):
    if i == 0:
        for j in range(1,W):
            if po[i][j] == ".":
                if aa[i][j-1][1] == 0:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1)
                    aa[i][j][1] = 3
                elif aa[i][j-1][1] == 1 or aa[i][j-1][1] == 3:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0])
                    aa[i][j][1] = 1
            else:
                aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0])

    else:
        for j in range(W):
            if j == 0:
                if po[i][j] == ".":
                    if aa[i-1][j][1] == 0:
                        aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0]+1)
                        aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 3 or aa[i-1][j][1] == 2:
                        aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0])
                        aa[i][j][1] = 2
                else:
                    aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0])
            else:
                if po[i][j] == ".":
                    if aa[i-1][j][1] == 0 or aa[i-1][j][1] == 1:
                        if aa[i][j-1][1] == 0 or aa[i][j-1][1] == 2:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 2:
                        if aa[i][j-1][1] == 0 or aa[i][j-1][1] == 2:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 3 or aa[i][j-1][1] == 2:
                        if aa[i][j-1][1] == 0:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                else:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])


print(min(aaa[-1][-1][0],aa[-1][-1][0]))

Submission status: Wrong Answer

Solution code:
from collections import deque
import sys
sys.setrecursionlimit(10 ** 9)
# import numpy as np
# 答えの提出の時にi+1とj+1は忘れないように
h, w = map(int, input().split())
maze = [[-1 for i in range(w)] for j in range(h)]

INF = h*w
countBlack = [[INF for i in range(w)] for j in range(h)]

for i in range(h):
    maze[i] = input()

sx=0
sy=0
queue = deque()
queue.append((sy,sx))
countBlack[sy][sx] = int(maze[0][0]== '#')

while queue:
    y, x = queue.popleft()
    for i,j in [(1,0),(0,1)]:
        ny, nx = y+i, x+j
        if 0 <= nx < w and 0 <= ny < h:
            if countBlack[ny][nx] >= countBlack[y][x]+1:
                if maze[ny][nx] == '#':
                    countBlack[ny][nx] = countBlack[y][x] + 1
                else:
                    countBlack[ny][nx] = countBlack[y][x]
                if ny != h-1 or nx != w-1:
                    queue.append((ny, nx))
                elif countBlack[ny][nx]==0:
                    print(0)
                    exit()

print(countBlack[h-1][w-1])

Submission status: Wrong Answer

Solution code:
input = raw_input
h, w = map(int, input().split(" "))
gh = h - 1
gw = w - 1

#dot_coords = []
#for hi in range(h):
#    wi = 0
#    for c in input():
#        if c == ".":
#            dot_coords.append((wi, hi))
#        wi += 1
        
maps = [list(input()) for _ in range(h)]
num_maps = [[None for _ in range(w)] for _ in range(h)]

count = 0
def find(sx, sy, cur_cost):
    next_cost_coord = []
    global count
    num_r = 1
    found = False
    routes = [(sx, sy)]
    num_maps[sy][sx] = cur_cost
    count += 1

    pre = False
    if sx == 1 and sy == 1:
        pre = True

    while num_r >= 1 and not found:
        x, y = routes[0]
        routes = routes[1:]
        num_r -= 1

        for nx, ny in [(x+1, y), (x, y+1)]:
            if pre:
                pass
                #print("lennummap", len(num_maps))
                #print(num_maps, ny, nx)
                #print(x, y, nx, ny, num_maps[ny][nx], gw, gh, "routes", routes)

            if nx <= gw and ny <= gh:
                if num_maps[ny][nx] is None:
                    if maps[ny][nx] == ".":
                        num_maps[ny][nx] = cur_cost
                        if nx == gw and ny == gh:
                            found = True
                            return next_cost_coord, found
                        else:
                            routes.append((nx, ny))
                            num_r += 1
                    else:
                        next_cost_coord.append((nx, ny))
    return next_cost_coord, found

cur_coords = [(0, 0)]
if maps[0][0] == ".":
    cur_cost = 0
else:
    cur_cost = 1

while True:   
    #print("cur_cost", cur_cost, "cur_coords", cur_coords)
    next_coords = []
    for sx, sy in cur_coords:
        cur_nc_coord, found = find(sx, sy, cur_cost)
        next_coords += cur_nc_coord
        #print(cur_nc_coord, num_maps)
        found = num_maps[gh][gw] is not None
        if found:
            break
    #print("cur_cost", cur_cost,"num_maps", num_maps)
    if found:
        break
    else:
        #print("test")
        cur_coords = next_coords
        assert len(cur_coords) >= 1
        cur_cost += 1
        #print("cur_cost", cur_cost)

out = num_maps[gh][gw]
print(out)
#print(count)

Submission status: Wrong Answer

Solution code:
H,W=map(int,input().split())
s=[0 for i in range(0,H)]
for i in range(0,H):
    s[i]=input()

dp=[[-1 for i in range(W)] for j in range(H)]
if s[0][0]=='#':
    dp[0][0]=1
else:
    dp[0][0]=0
for i in range(1,H):
    if s[0][i-1]=='.' and s[0][i]=='#':
        dp[0][i]=dp[0][i-1]+1
    else:
        dp[0][i]=dp[0][i-1]

for i in range(1,H):
    for j in range(0,W):
        fromup=10**5
        fromleft=10**5
        if s[i-1][j]=='.' and s[i][j]=='#':
            fromup=dp[i-1][j]+1
        else:
            fromup=dp[i-1][j]
        if j!=0:
            if s[i][j-1]=='.' and s[i][j]=='#':
                fromleft=dp[i][j-1]+1
            else:
                fromleft=dp[i][j-1]
        dp[i][j]=min(fromup,fromleft)

print(dp[H-1][W-1])

Submission status: Wrong Answer

Solution code:
# coding: utf-8
# Your code here!

import sys
sys.setrecursionlimit(10**6)
readline = sys.stdin.readline
read = sys.stdin.read

h,w = [int(i) for i in readline().split()]
b = [readline() for _ in range(h)]

INF = 10**9

dp0 = [[INF]*w for _ in range(h)]
dp1 = [[INF]*w for _ in range(h)]

if b[-1][-1] == "#":
    dp1[-1][-1] = 0
    dp0[-1][-1] = 1
else:
    dp0[-1][-1] = dp1[-1][-1] = 0

for i in range(h-1,-1,-1):
    for j in range(w-1,-1,-1):
        if b[i][j] == "#":
            r = INF
            if i != h-1: r = min(r,1 + dp1[i+1][j])
            if j != w-1: r = min(r,1 + dp1[i][j+1])
            dp0[i][j] = min(dp0[i][j],r)

            r = INF
            if i != h-1: r = min(r,dp1[i+1][j],dp0[i+1][j])
            if j != w-1: r = min(r,dp1[i][j+1],dp0[i][j+1])
            dp1[i][j] =  min(dp1[i][j],r)
            
        else:
            r = INF
            if i != h-1: r = min(r,dp0[i+1][j])
            if j != w-1: r = min(r,dp0[i][j+1])
            dp0[i][j] =  min(dp0[i][j],r)
            
            r = INF
            if i != h-1: r = min(r,dp1[i+1][j] + 1)
            if j != w-1: r = min(r,dp1[i][j+1] + 1)
            dp1[i][j] = min(dp1[i][j],r)


#print(dp0)
#print(dp1)

if b[0][0] == "#":
    print(1+dp1[0][0])
else:
    print(dp0[0][0])

Submission status: Wrong Answer

Solution code:
H,W = map(int,input().split())
A = []
for i in range(H):
    b = list(input())
    A.append(b)
dp = [[10**9 for i in range(W)] for i in range(H)]


if A[0][0] == ".":
    dp[0][0] = 0
else:
    dp[0][0] = 1

i = 0
j = 0

p = []
for i in range(H):
    for j in range(W):
        p.append([i,j])

t = 0
while(True):
    if i < H-1 and A[i+1][j] == ".":
        dp[i+1][j] = min(dp[i+1][j],dp[i][j])
        dp[i+1][j] = min(dp[i+1][j-1],dp[i+1][j])
    if j < W-1 and A[i][j+1] == ".":
        dp[i][j+1] = min(dp[i][j+1],dp[i][j])
        dp[i][j+1] = min(dp[i][j+1],dp[i-1][j+1])
    if i < H-1 and A[i+1][j] == "#":
        dp[i+1][j] = min(dp[i+1][j], dp[i][j]+1)
        dp[i+1][j] = min(dp[i+1][j-1]+1, dp[i+1][j])
    if j < W-1 and A[i][j+1] == "#":
        dp[i][j+1] = min(dp[i][j+1], dp[i][j]+1)
        dp[i][j+1] = min(dp[i][j+1], dp[i-1][j+1]+1)

    i = p[t][0]
    j = p[t][1]

    t += 1
    if i == H - 1 and j == W-1:
        break

print(dp[H-1][W-1])

Submission status: Wrong Answer

Solution code:
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
from itertools import permutations,combinations,groupby
import sys,bisect,string,math,time,functools,random
def Golf():*a,=map(int,open(0))
def I():return int(input())
def S_():return input()
def IS():return input().split()
def LS():return [i for i in input().split()]
def LI():return [int(i) for i in input().split()]
def LI_():return [int(i)-1 for i in input().split()]
def NI(n):return [int(input()) for i in range(n)]
def NI_(n):return [int(input())-1 for i in range(n)]
def StoLI():return [ord(i)-97 for i in input()]
def ItoS(n):return chr(n+97)
def LtoS(ls):return ''.join([chr(i+97) for i in ls])
def GI(V,E,Directed=False,index=0):
    org_inp=[];g=[[] for i in range(n)]
    for i in range(E):
        inp=LI();org_inp.append(inp)
        if index==0:inp[0]-=1;inp[1]-=1
        if len(inp)==2:
            a,b=inp;g[a].append(b)
            if not Directed:g[b].append(a)
        elif len(inp)==3:
            a,b,c=inp;aa=(inp[0],inp[2]);bb=(inp[1],inp[2]);g[a].append(bb)
            if not Directed:g[b].append(aa)
    return g,org_inp
def GGI(h,w,search=None,replacement_of_found='.',mp_def={'#':1,'.':0}):
#h,w,g,sg=GGI(h,w,search=['S','G'],replacement_of_found='.',mp_def={'#':1,'.':0}) # sample usage
    mp=[1]*(w+2);found={}
    for i in range(h):
        s=input()
        for char in search:
            if char in s:
                found[char]=((i+1)*(w+2)+s.index(char)+1)
                mp_def[char]=mp_def[replacement_of_found]
        mp+=[1]+[mp_def[j] for j in s]+[1]
    mp+=[1]*(w+2)
    return h+2,w+2,mp,found
def TI(n):return GI(n,n-1)
def bit_combination(k,n=2):return [[tb//(n**bt)%n for bt in range(k)] for tb in range(n**k)]
def show(*inp,end='\n'):
    if show_flg:print(*inp,end=end)

YN=['YES','NO'];Yn=['Yes','No']
mo=10**9+7
inf=float('inf')
l_alp=string.ascii_lowercase
#sys.setrecursionlimit(10**7)
input=lambda: sys.stdin.readline().rstrip()

def ran_input():
    n=random.randint(4,16)
    rmin,rmax=1,10
    a=[random.randint(rmin,rmax) for _ in range(n)]
    return n,a

show_flg=False
show_flg=True


h,w=LI()
h,w,g,sg=GGI(h,w,search=['S','G'],replacement_of_found='.',mp_def={'#':1,'.':0})
dp=[10**6]*(h*w)
dp[1],g[1]=0,0

for j in range(h*w-h):
    if j//w==h-1 or j%w==w-1:continue
    dp[j+1]=min(dp[j]+1 if (g[j],g[j+1])==(0,1) else dp[j],dp[j+1])
    dp[j+w]=min(dp[j]+1 if (g[j],g[j+w])==(0,1) else dp[j],dp[j+w])

print(dp[(h-2)*w+w-2])

Submission status: Wrong Answer

Solution code:
# -*- coding: utf-8 -*-

#入力
H, W = map(int,input().split())
s = [list(map(str,list(input()))) for i in range(H)] 

#初期値
count1 = 0
count2 = 0
j = 0
k = 0

if s[j][k]=='#':
    count1 += 1
    count2 += 1


while  j+1<H or k+1<W:
    if j+1!=H and s[j+1][k] == '.':
            j += 1
    elif k+1!=W and s[j][k+1] == '.':
        k += 1
    elif j+1!=H and s[j+1][k] == '#' :
        count1 += 1
        j+=1
    elif k+1!=W and s[j][k+1] == '#':
        count1 += 1
        k+=1

    
j = 0
k = 0
    
while  j+1<H or k+1<W:
    if k+1!=W and s[j][k+1] == '.':
        k += 1
    elif j+1!=H and s[j+1][k] == '.':
        j += 1
    elif k+1!=W and s[j][k+1] == '#':
        count2 += 1
        k+=1
    elif j+1!=H and s[j+1][k] == '#' :
        count2 += 1
        j+=1
    

if count1<count2:
    count=count1
else:
    count=count2

print(count)

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 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
"""


H,W = m()

po = [list(input()) for i in range(H)]

aaa = [[[mod,0] for i in range(W)] for j in range(H)]
aa = [[[mod,0] for i in range(W)] for j in range(H)]

if po[0][0] == "#":
    aaa[0][0] = [1,3]
else:
    aaa[0][0] = [0,0]

for i in range(H):
    if i == 0:
        for j in range(1,W):
            if po[i][j] == "#":
                if aaa[i][j-1][1] == 0:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1)
                    aaa[i][j][1] = 3
                elif aaa[i][j-1][1] == 1 or aaa[i][j-1][1] == 3:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0])
                    aaa[i][j][1] = 1
            else:
                aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0])

    else:
        for j in range(W):
            if j == 0:
                if po[i][j] == "#":
                    if aaa[i-1][j][1] == 0:
                        aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0]+1)
                        aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 3 or aaa[i-1][j][1] == 2:
                        aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0])
                        aaa[i][j][1] = 2
                else:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i-1][j][0])
            else:
                if po[i][j] == "#":
                    if aaa[i-1][j][1] == 0 or aaa[i-1][j][1] == 1:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0]+1)
                            aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 2:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                    elif aaa[i-1][j][1] == 3:
                        if aaa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0]+1,aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 1:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                        elif aaa[i][j-1][1] == 3:
                            aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])
                            aaa[i][j][1] = 3
                else:
                    aaa[i][j][0] = min(aaa[i][j][0],aaa[i][j-1][0],aaa[i-1][j][0])

if po[0][0] == ".":
    aa[0][0] = [1,3]
else:
    aa[0][0] = [1,0]

for i in range(H):
    if i == 0:
        for j in range(1,W):
            if po[i][j] == ".":
                if aa[i][j-1][1] == 0:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1)
                    aa[i][j][1] = 3
                elif aa[i][j-1][1] == 1 or aa[i][j-1][1] == 3:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0])
                    aa[i][j][1] = 1
            else:
                aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0])

    else:
        for j in range(W):
            if j == 0:
                if po[i][j] == ".":
                    if aa[i-1][j][1] == 0:
                        aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0]+1)
                        aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 3 or aa[i-1][j][1] == 2:
                        aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0])
                        aa[i][j][1] = 2
                else:
                    aa[i][j][0] = min(aa[i][j][0],aa[i-1][j][0])
            else:
                if po[i][j] == ".":
                    if aa[i-1][j][1] == 0 or aa[i-1][j][1] == 1:
                        if aa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0]+1)
                            aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 2:
                        if aa[i][j-1][1] == 0 or aaa[i][j-1][1] == 2:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                    elif aa[i-1][j][1] == 3 or aaa[i][j-1][1] == 2:
                        if aa[i][j-1][1] == 0:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0]+1,aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 1:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                        elif aa[i][j-1][1] == 3:
                            aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])
                            aa[i][j][1] = 3
                else:
                    aa[i][j][0] = min(aa[i][j][0],aa[i][j-1][0],aa[i-1][j][0])



print(min(aaa[-1][-1][0],aa[-1][-1][0]))

Submission status: Wrong Answer

Solution code:
H,W=map(int,input().split())
L=[]
l=["*" for i in range(W+2)]
L.append(l)
for i in range(H):
    s=["*"]+list(input())+["*"]
    L.append(s)
L.append(l)
#print(L)

X=[1,0,-1,0]
Y=[0,1,0,-1]

cnt=0
if L[1][1]=="#":
    cnt+=1
    Q=[[1,1]]
    for i in range(10**6):
        if i==len(Q):
            break
        L[Q[i][0]][Q[i][1]]="."
        for j in range(2):
            if L[Q[i][0]+X[j]][Q[i][1]+Y[j]]=="#":
                Q.append([Q[i][0]+X[j],Q[i][1]+Y[j]])

C=[[10000 for i in range(W+2)]for j in range(H+2)]
Q=[(0,1,1)]
#print(L)
import heapq
heapq.heapify(Q)
for i in range(10**6):
    if len(Q)==0:
        break
    d,h,w=Q[0]
    heapq.heappop(Q)
    if C[h][w]==10000:
        C[h][w]=d
        for j in range(2):
            if C[h+X[j]][w+Y[j]]==10000 and L[h+X[j]][w+Y[j]]!="*":
                if L[h+X[j]][w+Y[j]]=="#" and L[h][w]==".":
                    heapq.heappush(Q,(d+1,h+X[j],w+Y[j]))
                else:
                    heapq.heappush(Q,(d,h+X[j],w+Y[j]))
print(C[H][W]+cnt)
#print(cnt)
#print(L)
#print(C)
#print(Q)

Submission status: Wrong Answer

Solution code:
def flip_sq(sy, sx):
    gy = sy
    gx = sx
    while True:
        if sx == W - 1:
            if sy < H - 1 and tiles[sy+1][sx] == "#":
                sy += 1
            else:
                break
        elif tiles[sy][sx+1] == "#":
            sx += 1
            if sy == H - 1:
                break
            if tiles[sy+1][sx] == "#":
                sy += 1
        else:
            break
    for y in range(gy, sy+1):
        for x in range(gx, sx+1):
            tiles[y][x] = flip[tiles[y][x]]

H, W = [int(i) for i in input().strip().split(" ")]
tiles = []
for i in range(H):
    tiles.append([i for i in input().strip()])

tile = {"#":1, ".":0}
flip = {"#":".", ".":"#"}
count = []
for i in range(H):
    count.append([])
    for j in range(W):
        count[i].append(0)

count[0][0] = tile[tiles[0][0]]
if tile[tiles[0][0]]:
    flip_sq(0, 0)

for y in range(H):
    for x in range(W):
        if y == 0:
            if x == 0:
                continue
            count[y][x] = count[y][x-1] + tile[tiles[y][x]]
        else:
            if x == 0:
                count[y][x] = count[y-1][x] + tile[tiles[y][x]]
            else:
                count[y][x] = min(count[y-1][x], count[y][x-1]) + tile[tiles[y][x]]
        if tile[tiles[y][x]]:
            flip_sq(y, x)

print(count[H-1][W-1])

Submission status: Wrong Answer

Solution code:
from collections import deque
import sys
input = sys.stdin.readline
import numpy as np

H, W = map(int, input().split())
c = [input() for _ in range(H)]
si = sj =0
flg=(c[0][0]=="#")

dist = [[-1] * W for _ in range(H)]
dist[0][0] = 0
queue = deque()
queue.append((0,0))
move = [(1, 0), (0, 1)]#,(-1,0),(0,-1)]
while queue:
    i, j = queue.popleft()
    for di, dj in move:
        ni, nj = i+di, j+dj
        if 0 <= ni < H and 0 <= nj < W and dist[ni][nj] == -1:
            if c[ni][nj] == c[i][j]:
                dist[ni][nj] =dist[i][j]
                queue.appendleft((ni,nj))
            else:
                dist[ni][nj] =dist[i][j] +1
                queue.append((ni,nj))
                
print((dist[-1][-1])//2+flg)           
#print(np.array(dist))