[LeetCode] Merge Intervals

[1,3],[2,6],[8,10],[15,18]

[1,6],[8,10],[15,18]

/**
* 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 comp(const Interval &lhs, const Interval &rhs)
{
return lhs.start < rhs.start;
}

class Solution {
private:
vector<Interval> ret;
public:
vector<Interval> merge(vector<Interval> &intervals) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
ret.clear();

sort(intervals.begin(), intervals.end(), comp);
for(int i = 0; i < intervals.size(); i++)
if (ret.size() == 0)
ret.push_back(intervals[i]);
else
{
int size = ret.size();
if (ret[size-1].start <= intervals[i].start && intervals[i].start <= ret[size-1].end)
ret[size-1].end = max(ret[size-1].end, intervals[i].end);
else
ret.push_back(intervals[i]);
}

return ret;
}
};