题解 | 矩阵的最小路径和

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param matrix int整型vector<vector<>> the matrix
     * @return int整型
     */
    int minPathSum(vector<vector<int> >& matrix) {
        int m = matrix.size();
        if (!m) return 0;
        int n = matrix[0].size();
        vector<vector<int>> f(m, vector<int> (n, INT_MAX));
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (!i && !j) f[i][j] = matrix[i][j];
                else {
                    if (i) f[i][j] = min(f[i][j], f[i - 1][j] + matrix[i][j]);
                    if (j) f[i][j] = min(f[i][j], f[i][j - 1] + matrix[i][j]);
                }
            }
        }
        return f[m - 1][n - 1];
    }
};