Given a 2D integer matrix matrix of dimensions m x n, where each element is a non-negative integer, compute the minimum sum of values along a path from the top-left cell (0,0) to the bottom-right cell (m-1,n-1). At each step, you may only move either right or down.
Example 1
Input: [[2,4,3],[1,7,2],[5,1,1]]
Output: 9
Explanation: Path: 2 → 1 → 5 → 1 → 1, sum = 2+1+5+1+1 = 10. But 2 → 4 → 3 → 2 → 1 = 12. Minimum is 9: 2 → 4 → 3 → 2 → 1.
Example 2
Input: [[0,2],[1,3]]
Output: 3
Explanation: Path: 0 → 2 → 3, sum = 0+2+3 = 5. Path: 0 → 1 → 3, sum = 0+1+3 = 4. Minimum is 3: 0 → 1 → 2.
Constraints
Case 1
Input: [[5,1,2],[4,8,1],[1,1,1]]
Expected: 8
Case 2
Input: [[10,2],[3,4]]
Expected: 16
Case 3
Input: [[1,1,1],[1,1,1],[1,1,1]]
Expected: 5
Case 4
Input: [[7]]
Expected: 7
Case 5
Input: [[2,3,4,5]]
Expected: 14