LeetCode: Triangle

基本一次过
 1 class Solution {
 2 public:
 3     int minimumTotal(vector<vector<int> > &triangle) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         if (!triangle.size()) return 0;
 7         if (triangle.size() == 1) return triangle[0][0];
 8         vector<int> pre = triangle[0];
 9         for (int i = 1; i < triangle.size(); i++) {
10             vector<int> tmp = pre;
11             for (int j = 0; j < pre.size(); j++) {
12                 if (!j) tmp[j] = pre[j] + triangle[i][j];
13                 else tmp[j] = min(pre[j-1], pre[j]) + triangle[i][j];
14             }
15             tmp.push_back(triangle[i][i]+pre[pre.size()-1]);
16             pre = tmp;
17         }
18         int ret = pre[0];
19         for (int i = 1; i < pre.size(); i++) ret = min(ret, pre[i]);
20         return ret;
21     }
22 };