标签:style blog io ar color sp for on div
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.
class Solution { public: int minimumTotal(vector<vector<int> > &triangle) { int n = triangle.size(); vector<int> dp(n, 0); vector<int> tmp(n, 0); dp[0] = triangle[0][0]; for(int i=1;i<n;i++){ for(int j=0;j<=i;j++){ if( j>=1 && j <= i-1){ tmp[j] = min(dp[j-1], dp[j]) + triangle[i][j]; } else if(j==0){ tmp[j] = triangle[i][j] + dp[j]; } else if(j == i){ tmp[j] = triangle[i][j] + dp[j-1]; } } dp.swap(tmp); } int ans = dp[0]; for(int i=0;i<n;i++){ if(ans>dp[i]) ans = dp[i]; } return ans; } };
标签:style blog io ar color sp for on div
原文地址:http://www.cnblogs.com/code-swan/p/4141114.html