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.
1 class Solution { 2 public: 3 int minPathSum(vector<vector<int>>& grid) { 4 if(grid.size() == 0 || grid[0].size() == 0){ 5 return 0; 6 } 7 8 int row = grid.size(); 9 int col = grid[0].size(); 10 11 int dp[row][col]; 12 13 dp[0][0] = grid[0][0]; 14 15 for(int i = 1; i < row; i++){ 16 dp[i][0] = dp[i-1][0] + grid[i][0]; 17 } 18 19 for(int j = 1; j < col; j++){ 20 dp[0][j] = dp[0][j-1] + grid[0][j]; 21 } 22 23 for(int i = 1; i < row; i++){ 24 for(int j =1; j < col; j++){ 25 dp[i][j] = min(dp[i-1][j] , dp[i][j-1]) + grid[i][j]; 26 } 27 } 28 return dp[row-1][col-1]; 29 } 30 };