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).

 

在输入的数组中直接修改，这样就不需要额外的空间了，不知道这样符合题目的本意不，不过已AC。

1 class Solution { 2 public: 3     int minimumTotal(vector
     
      
        > &triangle) { 4         if (triangle.size() == 1) { 5             return triangle[0][0]; 6         } 7         int min_sum = INT_MAX; 8         for (int i = 1; i < triangle.size(); ++i) { 9             for (int j = 0; j <= i; ++j) {10                 if (j == 0) {11                     triangle[i][j] += triangle[i-1][j];12                 } else if (j == i) {13                     triangle[i][j] += triangle[i-1][j-1];14                 } else {15                     triangle[i][j] += min(triangle[i-1][j-1], triangle[i-1][j]);16                 }17                 if (i == triangle.size() - 1) {18                     min_sum = min(min_sum, triangle[i][j]);19                 }20             }21         }22         return min_sum;23     }24 };