3128. 直角三角形

3128. 直角三角形

题目链接：3128. 直角三角形

代码如下：

//参考链接:https://leetcode.cn/problems/right-triangles/solutions/2758892/cheng-fa-yuan-li-pythonjavacgo-by-endles-7469
class Solution
{
public:
	long long numberOfRightTriangles(vector<vector<int>>& grid)
	{
		vector<int> col_sum(grid[0].size(), -1);// 提前减一
		for (auto& row : grid)
		{
			for (int j = 0; j < row.size(); j++)
			{
				col_sum[j] += row[j];
			}
		}

		long long res = 0;
		for (auto& row : grid)
		{
			int row_sum = reduce(row.begin(), row.end(), 0) - 1;// 提前减一
			for (int j = 0; j < row.size(); j++)
			{
				if (row[j] == 1) { res += col_sum[j] * row_sum; }
			}
		}
		return res;
	}
};