Leetcode #120 Triangle

Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.

For example, given the following triangle

[     [2],    [3,4],   [6,5,7],  [4,1,8,3]]

The minimum path sum from top to bottom is 11 (i.e., 2 + 3 + 5 + 1 = 11).

Note:

Bonus point if you are able to do this using only O(n) extra space, where n is the total number of rows in the triangle.

Difficulty:Medium

class Solution {public:    int minimumTotal(vector<vector<int>>& triangle) {        int n = triangle.size();        if(n==0)           return 0;        for(int i = 1;i<n;i++)        {            triangle[i][0]+=triangle[i-1][0];            triangle[i][i]+=triangle[i-1][i-1];            for(int j = 1;j<i;j++)            {                triangle[i][j] = triangle[i][j] + min(triangle[i-1][j-1],triangle[i-1][j]);            }        }        sort(triangle[n-1].begin(),triangle[n-1].end());        return triangle[n-1][0];    }};