LeetCode---Merge Intervals

 1 /**
 2  * Definition for an interval.
 3  * struct Interval {
 4  *     int start;
 5  *     int end;
 6  *     Interval() : start(0), end(0) {}
 7  *     Interval(int s, int e) : start(s), end(e) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     vector<Interval> merge(vector<Interval> &intervals) {
13         typedef pair<int, int> pii;
14         vector<pii> my_pair;
15         for (unsigned int i = 0; i < intervals.size(); i++) {
16             my_pair.push_back(pii(intervals[i].start, intervals[i].end));
17         }
18         sort(my_pair.begin(), my_pair.end());
19         vector<Interval> ans;
20         //输入为空
21         if (intervals.size() == 0) {
22             return ans;
23         }
24         int beg = my_pair[0].first, ed = my_pair[0].second;
25         for (unsigned int i = 1; i < my_pair.size(); i++) {
26             if (my_pair[i].first <= ed) {
27                 ed = max(my_pair[i].second, ed);
28             } else {
29                 ans.push_back(Interval(beg, ed));
30                 beg = my_pair[i].first;
31                 ed = my_pair[i].second;
32             }
33         }
34         //处理最后一个数据
35         if (ans.size() == 0 || beg > ans[ans.size()-1].start) {
36             ans.push_back(Interval(beg, ed));
37         }
38         
39         return ans;
40     }
41 };