LintCode_110.java

public class LintCode_110 {
    /**
     * @param grid: a list of lists of integers.
     * @return: An integer, minimizes the sum of all numbers along its path
     */
    public int minPathSum(int[][] grid) {
        // write your code here
        if(grid == null || grid.length == 0 || grid[0].length == 0){
            return 0;
        }
        
        int m = grid.length;
        int n = grid[0].length;
        int[][] f = new int[m][n];
        f[0][0] = grid[0][0];
        for(int i = 1; i < n; i++){
            f[0][i] = f[0][i - 1] + grid[0][i];
        }
        
        for(int i = 1; i < m; i++){
            f[i][0] = f[i - 1][0] + grid[i][0];
        }
        
        for(int i = 1; i < m; i++){
            for(int j = 1; j < n; j++){
                f[i][j] = Math.min(f[i][j - 1], f[i - 1][j]) + grid[i][j];
                
            }
        }
        return f[m - 1][n - 1];
    }
}