Leetcode每日一题
题目链接: 861. 翻转矩阵后的得分
难度: 中等
解题思路: 要使翻转后的值尽可能大,那么使得它的首位为1,每一列的1尽可能多即可。具体做法为:翻转行使得第一行一定为1,翻转列使得每一列的1尽可能多。翻转完再计算值。
题解:

class Solution:
    def matrixScore(self, A: List[List[int]]) -> int:
        if len(A) == 0:
            return 0
        # 翻转行使得第一行一定为1,翻转列使得每一列的1尽可能多

        factor = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576]
        
        # 第一列翻转为1
        for i in range(len(A)):
            if A[i][0] == 0:
                for j in range(len(A[i])):
                    A[i][j] = 1 if A[i][j] == 0 else 0
        
        # 使得每一列的1尽可能多     
        for j in range(1, len(A[0])):
            col = [A[i][j] for i in range(len(A))]
            if col.count(1) < len(A) / 2:
                for i in range(len(A)):
                    A[i][j] = 1 if A[i][j] == 0 else 0
        
        # print(A)
        # 加和
        res = 0
        for i in range(len(A)):
            for j in range(len(A[i])):
                res += factor[int(len(A[i]) - j - 1)] if A[i][j] == 1 else 0 

        return res