leetcode--Merge Intervals

[code]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].

[code]/**

* Definition for an interval.

* struct Interval {

* int start;

* int end;

* Interval() : start(0), end(0) {}

* Interval(int s, int e) : start(s), end(e) {}

* };

*/

bool lc(const Interval &a,const Interval &b)

{

return a.start<b.start;

}

class Solution {

public:

vector<Interval> merge(vector<Interval> &intervals) {

// Start typing your C/C++ solution below

// DO NOT write int main() function

vector<Interval>result;

if(intervals.empty())return result;

std::sort(intervals.begin(),intervals.end(),lc);

Interval cur=intervals[0];

int len=intervals.size();

if(len==1)return intervals;

int i=1;

while(i<len)

{

if(cur.end>=intervals[i].start)

{

cur.end=max(intervals[i].end,cur.end);

}

else

{

result.push_back(cur);

cur=intervals[i];

}

i++;

}

if(result.empty()||result.back().end<cur.start)result.push_back(cur);

return result;

}

};