逆时针打印矩阵

import sys
def dfs(roadlist,res,x,y,rows,cols):
    if x==rows-1 and y==cols-1 :
        res.append("(%s,%s)" %(x,y))
        return True
    elif x>=rows or y>=cols or x<0 or y<0:
        return False
    elif roadlist[x][y]==-1:
        return False
    elif roadlist[x][y]==0:
        res.append("(%s,%s)" %(x,y))
        roadlist[x][y]= -1
        return dfs(roadlist, res, x-1, y, rows, cols) \
            or dfs(roadlist, res, x+1, y, rows, cols) \
            or dfs(roadlist, res, x, y-1, rows, cols) \
            or dfs(roadlist, res, x, y+1, rows, cols)


try:
    while True:
        rows,cols=map(int,sys.stdin.readline().split())
        roadlist=[list(map(int,sys.stdin.readline().split())) for i in range(rows)]
        res=[]
       # isvisit=[[0 for i in range(cols)] for j in range(rows)]
        if dfs(roadlist,res,0,0,rows,cols):
            for i in res:
                print(i)
except:
    pass

这个代码明明是错的，也可以通过