Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.
Note: You can only move either down or right at any point in time.
题目解析:
找一条路径,从左上到右下使其和最小。
还是利用动态规划:f[i][j] = min(f[i-1][j], f[i][j-1]) + a[i][j]
class Solution { public: int minPathSum(vector<vector<int> > &grid) { if(grid.size() == 0) return 0; int row = grid.size(); int col = grid[0].size(); for(int i = 1;i < col;i++) grid[0][i] = grid[0][i-1]+grid[0][i]; for(int i = 1;i < row;i++) grid[i][0] = grid[i][0] + grid[i-1][0]; for(int i = 1;i < row;i++){ for(int j = 1;j < col;j++){ grid[i][j] += min(grid[i-1][j],grid[i][j-1]); } } return grid[row-1][col-1]; } };