64. Minimum Path Sum
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.
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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
Solution
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class Solution {
public:
int minPathSum(vector<vector<int>>& grid) {
int rows = grid.size();
int cols = grid[0].size();
vector<vector<int>> results(rows, vector<int>(cols, 0));
results[0][0] = grid[0][0];
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
if (i > 0 && j > 0) {
results[i][j] = std::min(results[i - 1][j], results[i][j - 1]) + grid[i][j];
} else if (i > 0 && j == 0) {
results[i][j] = results[i - 1][j] + grid[i][j];
} else if (i == 0 && j > 0) {
results[i][j] += results[i][j - 1] + grid[i][j];
}
}
}
return results[rows - 1][cols - 1];
}
};
