golang 解法, 执行用时: 8 ms, 内存消耗: 3.6 MB, 提交时间: 2021-06-11 17:01:24

func projectionArea(grid [][]int) int {
    n := len(grid)
    ans := 0
    for i := 0; i < n; i++ {
        rMax, cMax := 0, 0
        for j := 0; j < n; j++ {
            if grid[i][j] > 0 {
                ans++
            }
            rMax = max(grid[i][j], rMax)
            cMax = max(grid[j][i], cMax)
        }
        ans += rMax + cMax
    }

    return ans

}

func max(x, y int) int {
	if x > y {
		return x
	}
	return y
}