Question Definition
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:
[[1,3,1],
[1,5,1],
[4,2,1]]
Given the above grid map, return 7. Because the path 1→3→1→1→1 minimizes the sum.
My Java Solution
public int minPathSum(int[][] grid) {
if(grid.length == 0) return 0;
int[][] dp = new int[grid.length + 1][grid[0].length + 1];
for(int i = 1; i <= grid.length; i++){
for(int j = 1; j <= grid[0].length; j++){
if(i == 1)
dp[i][j] = dp[i][j - 1] + grid[i - 1][j - 1];
else if(j == 1)
dp[i][j] = dp[i - 1][j] + grid[i - 1][j - 1];
else
dp[i][j] = Math.min(dp[i - 1][j] + grid[i - 1][j - 1], dp[i][j - 1] + grid[i - 1][j - 1]);
}
}
return dp[grid.length][grid[0].length];
}
Comments