Problem p03263 (python)

Fixed submission:
import sys, bisect, math, itertools, string, queue, copy
# import numpy as np
# import scipy
from collections import Counter,defaultdict,deque
from itertools import permutations, combinations
from heapq import heappop, heappush
input = sys.stdin.readline
sys.setrecursionlimit(10**8)
mod = 10**9+7
def inp(): return int(input()) # n=1
def inpm(): return map(int,input().split()) # x=1,y=2
def inpl(): return list(map(int, input().split())) # a=[1,2,3,4,5,...,n]
def inpls(): return list(input().split())  # a=['1','2','3',...,'n']
def inplm(n): return list(int(input()) for _ in range(n)) # x=[] 複数行
def inplL(n): return [list(input()) for _ in range(n)]
def inplT(n): return [tuple(input()) for _ in range(n)]
def inpll(n): return [list(map(int, input().split())) for _ in range(n)] # [[1,1,1,1],[2,2,2,2],[3,3,3,3]] 
def inplls(n): return sorted([list(map(int, input().split())) for _ in range(n)]) # [[1,1,1,1],[2,2,2,2],[3,3,3,3]] 
def graph():
    n=inp()
    g=[[] for _ in range(n)]
    for i in range(n):
        a = inp()
        a -= 1
        g[i].append(a)
        g[a].append(i)
    return n,g

def rotation_find(n,m,g): # 迷路を外側からぐるぐると探索 
    did = [[False for _ in range(m+2)] for _ in range(n+2)]
    for i in range(n+2):
        did[i][0]=True
        did[i][m+1]=True
    for i in range(m+2):
        did[0][i]=True
        did[n+1][i]=True
    x = 1
    y = 1
    key = 1
    ans = []
    while True:
        did[x][y] = True
        key1 = 0
        if g[x-1][y-1]%2 != 0:
            key1 = 1
        a,b = x,y
        if key==1:
            x+=1
        elif key==2:
            y+=1
        elif key==3:
            x-=1
        elif key==4:
            y-=1
        if key==1 and did[x][y]:
            x-=1
            y+=1
            key=2
        elif key==2 and did[x][y]:
            y-=1
            x-=1
            key=3
        elif key==3 and did[x][y]:
            x+=1
            y-=1
            key=4
        elif key==4 and did[x][y]:
            x+=1
            y+=1
            key=1
        if did[x][y]:
            break
        if key1:
            g[a-1][b-1] -= 1
            g[x-1][y-1] += 1
            ans.append((a,b,x,y))
    return ans

def main():
    h,w = inpm()
    a = inpll(h)
    ans = rotation_find(h,w,a)
    print(len(ans))
    for i in range(len(ans)):
        print(*ans[i])
 
if __name__ == "__main__":
    main()

Buggy submission (verdict: Runtime Error):
import sys, bisect, math, itertools, string, queue, copy
# import numpy as np
# import scipy
from collections import Counter,defaultdict,deque
from itertools import permutations, combinations
from heapq import heappop, heappush
input = sys.stdin.readline
sys.setrecursionlimit(10**8)
mod = 10**9+7
def inp(): return int(input()) # n=1
def inpm(): return map(int,input().split()) # x=1,y=2
def inpl(): return list(map(int, input().split())) # a=[1,2,3,4,5,...,n]
def inpls(): return list(input().split())  # a=['1','2','3',...,'n']
def inplm(n): return list(int(input()) for _ in range(n)) # x=[] 複数行
def inplL(n): return [list(input()) for _ in range(n)]
def inplT(n): return [tuple(input()) for _ in range(n)]
def inpll(n): return [list(map(int, input().split())) for _ in range(n)] # [[1,1,1,1],[2,2,2,2],[3,3,3,3]] 
def inplls(n): return sorted([list(map(int, input().split())) for _ in range(n)]) # [[1,1,1,1],[2,2,2,2],[3,3,3,3]] 
def graph():
    n=inp()
    g=[[] for _ in range(n)]
    for i in range(n):
        a = inp()
        a -= 1
        g[i].append(a)
        g[a].append(i)
    return n,g

def rotation_find(n,m,g): # 迷路を外側からぐるぐると探索 
    did = [[False for _ in range(m+2)] for _ in range(n+2)]
    for i in range(n+2):
        did[i][0]=True
        did[i][m+1]=True
    for i in range(m+2):
        did[0][i]=True
        did[n+1][i]=True
    x = 1
    y = 1
    key = 1
    ans = []
    while True:
        did[x][y] = True
        key1 = 0
        if g[x-1][y-1]%2 != 0:
            key1 = 1
        a,b = x,y
        if key==1:
            x+=1
        elif key==2:
            y+=1
        elif key==3:
            x-=1
        elif key==4:
            y-=1
        if key==1 and did[x][y]:
            x-=1
            y+=1
            key=2
        elif key==2 and did[x][y]:
            y-=1
            x-=1
            key=3
        elif key==3 and did[x][y]:
            x+=1
            y-=1
            key=4
        elif key==4 and did[x][y]:
            x+=1
            y+=1
            key=1
        if key1:
            g[a-1][b-1] -= 1
            g[x-1][y-1] += 1
            ans.append((a,b,x,y))
        if did[x][y]:
            break
    return ans

def main():
    h,w = inpm()
    a = inpll(h)
    ans = rotation_find(h,w,a)
    print(len(ans))
    for i in range(len(ans)):
        print(*ans[i])
 
if __name__ == "__main__":
    main()