LeetCode Link: 64. Minimum Path Sum
Language: C#
Problem Statement
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.
Example 1:
Input: grid = [[1,3,1],[1,5,1],[4,2,1]]
Output: 7
Explanation: Because the path 1 → 3 → 1 → 1 → 1 minimizes the sum.
Example 2:
Input: grid = [[1,2,3],[4,5,6]]
Output: 12
Constraints:
- m == grid.length
- n == grid[i].length
- 1 <= m, n <= 200
- 0 <= grid[i][j] <= 200
Solution
public class Solution
{
public int MinPathSum(int[][] grid)
{
var m = grid.Length;
var n = grid[0].Length;
var n2 = new int[m][];
for (int i=0; i<m; i++)
{
n2[i] = new int[n];
}
n2[0][0] = grid[0][0];
for (int i=1; i<n; i++)
{
n2[0][i] = n2[0][i-1] + grid[0][i];
}
for (int i=1; i<m; i++)
{
n2[i][0] = n2[i-1][0] + grid[i][0];
}
for (int i=1; i<m; i++)
{
for (int j=1; j<n; j++)
{
int o1 = n2[i][j-1] + grid[i][j];
int o2 = n2[i-1][j] + grid[i][j];
n2[i][j] = Math.Min(o1, o2);
}
}
return n2[m-1][n-1];
}
}