LeetCode #807. Max Increase to Keep City Skyline 保持城市天际线

https://leetcode-cn.com/problems/max-increase-to-keep-city-skyline/

 

执行用时 : 3 ms, 在Max Increase to Keep City Skyline的Java提交中击败了95.31% 的用户 内存消耗 : 37.7 MB, 在Max Increase to Keep City Skyline的Java提交中击败了92.13% 的用户

最直接的思路：

1. 获取矩阵的每一行最大值和每一列最大值
2. 根据上述最大值来“提高”建筑

class Solution {
    public int maxIncreaseKeepingSkyline(int[][] grid) {
        int result = 0;
        int rowSize = grid.length;
        // rowMax 每行最大数值
        int[] rowMax = new int[rowSize];
        
        int colSize = grid[0].length;
        // colMax 每列最大数值
        int[] colMax = new int[colSize];
        
        int i = 0;
        int j = 0;
        
        for (i = 0; i < rowSize; i++) {
            rowMax[i] = 0;
            for (j = 0; j < colSize; j++) {
                if (grid[i][j] > rowMax[i]) {
                    rowMax[i] = grid[i][j];
                }
            }
        }
        
        for (j = 0; j < colSize; j++) {
            colMax[j] = 0;
            for (i = 0; i < rowSize; i++) {
                if (grid[i][j] > colMax[j]){
                    colMax[j] = grid[i][j];
                }
            }
        }
        
        for (i = 0; i < rowSize; i++) {
            for (j = 0; j < colSize; j++) {
                if (rowMax[i] > colMax[j]) {
                    result += colMax[j] - grid[i][j];
                } else {
                    result += rowMax[i] - grid[i][j];
                }
            }
        }
        
        return result;
    }
}