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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).

解題思路:

求金字塔的最短路徑,當中路徑僅僅能走下一行的相鄰位置。

我們将路徑相疊加,有兩條路徑的将會選一個路徑疊加較小的那條路徑值。

代碼例如以下:

class Solution {
public:
    int minimumTotal(vector<vector<int>>& triangle) {
       if(triangle.size()==0) return 0;
        int n=triangle.size();
        int m=triangle[0].size();
        vector<int> temp=triangle[0];
        
        for(int i=1;i<triangle.size();i++)
        {
            temp.push_back(0);
            for(int j=0;j<triangle[i].size();j++)
            {
                if(j==0)
                {
                    temp[j]+=triangle[i][j];
                }
                else if(j==triangle[i].size()-1)
                {
                    temp[j]=triangle[i-1][j-1]+triangle[i][j];
                }
                else 
                {
                    temp[j]=(triangle[i][j]+triangle[i-1][j-1])>(triangle[i][j]+triangle[i-1][j])?      

(triangle[i][j]+triangle[i-1][j]):(triangle[i][j]+triangle[i-1][j-1]); }

}

triangle[i]=temp;

}

sort(temp.begin(),temp.end());

return temp[0];

}

};