Minimum Path Sum

使用带记录的递归。

int result[500][500];
    int min(int a, int b){
        if(a < b)
            return a;
        return b;
    }
    void initialize(){
        int i,j;
        for(i = 0; i < 500; i++){
            for(j = 0; j < 500; j++){
                result[i][j] = -1;
            }
        }
    }
    int getResult(vector<vector<int>> &grid, int m, int n){
        if(result[m][n] != -1)
            return result[m][n];
        int tmp = 0;
        int height = grid.size(), width = grid[0].size();
        if(m == 1){
            int i;
            for(i = width-n; i < width; i++){
                tmp += grid[height-m][i];
            }
            result[m][n] = tmp;
            return tmp;
        }
        if(n == 1){
            int i;
            for(i = height-m; i < height; i++){
                tmp += grid[i][width-n];
            }
            result[m][n] = tmp;
            return tmp;
        }
        tmp = grid[height-m][width-n] + min(getResult(grid, m-1, n), getResult(grid, m, n-1));
        result[m][n] = tmp;
        return tmp;
    }
    int minPathSum(vector<vector<int> > &grid) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int m = grid.size();
        if(m == 0)
            return 0;
        int n = grid[0].size();
        if(n == 0)
            return 0;
        initialize();
        return getResult(grid, m, n);
    }