leetcode-Merge Intervals

Given a collection of intervals, merge all overlapping intervals.

For example,
Given [1,3],[2,6],[8,10],[15,18],
return [1,6],[8,10],[15,18].

思路：先按照start进行排序，再合并。

代码：

bool TIsShort(const Interval &s1,const Interval &s2)
{
return s1.start<s2.start;
}


class Solution {
public:


    vector<Interval> merge(vector<Interval> &intervals) {
        if(intervals.empty())
{
return intervals;
}
sort(intervals.begin(),intervals.end(),TIsShort);


        vector<Interval> ::iterator it=intervals.begin();
while((it+1) != intervals.end())
{
vector<Interval> ::iterator temp=it+1;
if((*it).end>=(*temp).start)
{
if((*it).end < (*temp).end)
{
(*it).end=(*temp).end;
}
intervals.erase(temp);
}
else
{
++it;
}
}
return intervals;
    }
};