64. Minimum Path Sum

DP

class Solution {
    public int minPathSum(int[][] grid) {
        int row = grid.length;
        int col = grid[0].length;
        int[] dp = new int[col];
        dp[0]=grid[0][0];
        for(int j = 1;j<col;j++)
            { 
                    dp[j]=grid[0][j]+dp[j-1];
            }
        for(int i = 1 ;i<row;i++)
        {
            for(int j = 0;j<col;j++)
            {
                if(j==0)
                {
                    dp[j]+=grid[i][j];
                }
                else
                {
                    dp[j]=Math.min(dp[j]+grid[i][j],dp[j-1]+grid[i][j]);
                }
            }
        }
        return dp[col-1];
    }
}