leetcode-Merge Intervals

描述：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]

.

/**
* Definition for an interval.
* struct Interval {
* int start;
* int end;
* Interval() : start(0), end(0) {}
* Interval(int s, int e) : start(s), end(e) {}
* };
*/

找出公共区间，并合并

本题首先要按照Interval的start进行排序

static bool comp(const Interval& i1,const Interval& i2)
{
return i1.start < i2.start;
}

sort(intervals.begin(),intervals.end(),comp);

完整代码

class Solution {
public:
static bool comp(const Interval& i1,const Interval& i2)
{
return i1.start < i2.start;
}
vector<Interval> merge(vector<Interval> &intervals) {
if(intervals.size()==0)
{
return intervals;
}
sort(intervals.begin(),intervals.end(),comp);vector<Interval> result;
result.push_back(intervals[0]);
int j=0;
for(int i=1;i<intervals.size();i++)
{
if((intervals[i].start<result[j].end || intervals[i].start==result[j].end) && intervals[i].end>result[j].end)
{
result[j].end=intervals[i].end;
}
else if(intervals[i].start>result[j].end)
{
result.push_back(intervals[i]);
j++;
}
}
return result;
}
};