Leetcode 64. Minimum Path Sum in C [C語言]
==
###### tags:`Leetcode` `DP`

## Description
(medium)
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

## 怎麼解呢
因為他有限制只能往右或是往下，所以不用其他graph的算法，只要DP從左上角填表格填下去右下角就可以得到最佳解了。
所以只要看自己的左邊跟上面哪個比較小就好了。


int min(int a, int b){
    if(a>b) return b;
    else    return a;
}

int minPathSum(int** grid, int gridSize, int* gridColSize){
    int i;
    int j;
    for(i=1; i<(*gridColSize); i++){
        grid[0][i]=grid[0][i]+grid[0][i-1];
    }
    for(i=1; i<gridSize; i++){
        grid[i][0]=grid[i-1][0]+grid[i][0];
        for(j=1; j<(*gridColSize); j++){
            grid[i][j]+=min(grid[i-1][j], grid[i][j-1]);
        }
    }
    return grid[gridSize-1][(*gridColSize)-1];
}

為了方便先把第一row處理掉，然後每個比自己的左還有上，也就是grid[i-1][j], grid[i][j-1]，一路比下去就有了

Runtime: 15 ms
Memory Usage: 7.4 MB
Your runtime beats 70.75 % of c submissions.