Problem Statement

Given a triangle array, return the minimum path sum from top to bottom.

For each step, you may move to an adjacent number of the row below. More formally, if you are on index i on the current row, you may move to either index i or index i + 1 on the next row.

Example 1:

Input: triangle = [[2],[3,4],[6,5,7],[4,1,8,3]]
Output: 11
Explanation: The triangle looks like:
23 4
 65 7
41 8 3
The minimum path sum from top to bottom is 2 + 3 + 5 + 1 = 11 (underlined above).

Example 2:

Input: triangle = [[-10]]
Output: -10

Problem Link

Triangle - LeetCode

Code

class Solution {
public:
    int minimumTotal(vector<vector<int>>& triangle) {
        
        int n = triangle.size();
        
        vector<vector<int>> dp(n,vector<int>(n));
        
        dp[0][0] = triangle[0][0];
        
        for(int i=1;i<n;i++)
        {
            for(int j=0;j<triangle[i].size();j++)
            {
                if(j==0)//left corner
                    dp[i][j] = triangle[i][j] + dp[i-1][j];
                
                else if(j==triangle[i].size()-1)//right corner
                    dp[i][j] = triangle[i][j] + dp[i-1][j-1];
                
                
                else
                    dp[i][j] = triangle[i][j] + min(dp[i-1][j],dp[i-1][j-1]);
                
                
                
                
                    
                    
            }
        }
        return *min_element(dp[n-1].begin(),dp[n-1].end());
    }
};