Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.
Note:
- You may assume the interval's end point is always bigger than its start point.
- Intervals like [1,2] and [2,3] have borders "touching" but they don't overlap each other.
Example 1:
Input: [ [1,2], [2,3], [3,4], [1,3] ] Output: 1 Explanation: [1,3] can be removed and the rest of intervals are non-overlapping.
Example 2:
Input: [ [1,2], [1,2], [1,2] ] Output: 2 Explanation: You need to remove two [1,2] to make the rest of intervals non-overlapping.
Example 3:
Input: [ [1,2], [2,3] ] Output: 0 Explanation: You don't need to remove any of the intervals since they're already non-overlapping.
讲真,一点都不想写这个的题解
被自己蠢哭了,告诉我这个题和看电视节目那个贪心入门有什么区别???
怎么还能第一关键字是start???后一个和前一个比较的是end,当然是第一关键字是end排序啊!!!
大二下开学还是老陈讲的啊………………
这都能写错,还搜题解…………
赶紧老实儿的一天刷一个题吧
/**
* 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 &a,const Interval &b)
{
if(a.end==b.end)return a.start<b.start;
return a.end<b.end;
}
class Solution {
public:
int eraseOverlapIntervals(vector<Interval>& intervals) {
if(intervals.size()==0) return 0;
sort(intervals.begin(),intervals.end(),comp);
int num=1;
int right=intervals[0].end;
for(int i=1;i<intervals.size();i++)
{
if(intervals[i].start<right) continue;
num++;
right=intervals[i].end;
}
return intervals.size()-num;
}
};