区间合并(c++实现)

裸题 就不放题目了

直接上代码

#include<iostream>
#include<algorithm>
using namespace std;
typedef pair<int,int> PII;
const int N = 100010;
PII q[N],s[N];

int n,cnt;


int main(){
    scanf("%d",&n);
    
    for(int i=1;i<=n;i++) scanf("%d%d",&q[i].first,&q[i].second);
    
    sort(q+1,q+n+1);
    int st =-1e9,ed=-1e9;
    for(int i=1;i<=n;i++){
        if(ed < q[i].first) {
            st=q[i].first,ed = max(ed,q[i].second);
            if(st!=-1e9) s[cnt++] = {st,ed};
        }else {
            ed = max(ed,q[i].second);
        }
        if(st != -1e9) s[cnt++] = {st,ed};
    }
    int res = 0;
    for(int i=1;i<cnt;i++){
        if(s[i].first!=s[i-1].first) res++;
    }
    cout<<(res+1)<<endl;
}