LeetCode #1582. Special Positions in a Binary Matrix

题目

1582. Special Positions in a Binary Matrix

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解题方法

设置一个字典记录矩阵中1的位置，遍历字典中的键，判断纵向和横向上的坐标是否在字典中，且不是该点，如果都没有就把它记录为满足条件的点。
时间复杂度：O(mn)
空间复杂度：O(mn)

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代码

class Solution:
    def numSpecial(self, mat: List[List[int]]) -> int:
        dic = {}
        for i in range(len(mat)):
            for j in range(len(mat[i])):
                if mat[i][j]:
                    dic[(i,j)] = 1
        
        rat = 0
        for key in dic.keys():
            colone = 0
            for i in range(len(mat)):
                if (i, key[1]) in dic and i != key[0]:
                    colone = 1
                    break
            if colone: continue
            
            rowone = 0
            for j in range(len(mat[0])):
                if (key[0], j) in dic and j != key[1]:
                    rowone = 1
                    break
            if rowone:
                pass
            else:
                rat += 1
        
        return rat