题解 | 合并区间

/**
 * struct Interval {
 *  int start;
 *  int end;
 *  Interval(int s, int e) : start(start), end(e) {}
 * };
 */
#include <bits/stdc++.h>
#include <vector>
using namespace std;
bool compare(Interval a, Interval b) {
    return a.start < b.start;
}
class Solution {
  public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param intervals Interval类vector
     * @return Interval类vector
     */


    vector<Interval> merge(vector<Interval>& intervals) {
        // write code here
        vector<Interval>a;
        if(intervals.size()==0)return intervals;
        sort(intervals.begin(), intervals.end(), compare);
        for (int i = 1; i < intervals.size(); i++) {
            if (intervals[i].start <= intervals[i - 1].end) {
                intervals[i].start = min(intervals[i - 1].start, intervals[i].start);
                intervals[i].end = max(intervals[i - 1].end, intervals[i].end);
            }else{
                a.push_back(intervals[i-1]);
            }
        }
        a.push_back(intervals[intervals.size()-1]);
        return a;
    }
};

经典的贪心思路，只需要排序后合并即可