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.
int minimumTotal(vector<vector<int> > &triangle) { int row = triangle.size(); vector<int>dp(triangle[row-1].size(),0); dp[0] = triangle[0][0]; for(int i=1; i<row; i++){ for(int j=triangle[i].size()-1; j>=0; j--){ if(j == triangle[i].size()-1){ dp[j] = dp[j-1] + triangle[i][j]; } else if(j == 0){ dp[0] = dp[0]+triangle[i][0]; } else{ dp[j] = min(dp[j],dp[j-1])+triangle[i][j]; } } } int minimum = INT_MAX; for(int i=0; i<dp.size(); i++){ minimum = min(minimum,dp[i]); } return minimum;}
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