算法练习：区间合并

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

typedef pair<int,int> PII;
vector<PII> segs;

void merge(vector<PII> &segs)
{
    vector<PII> res;
    sort(segs.begin(),segs.end());
    int st=-2e9,ed=-2e9;
    for(auto seg:segs)
    {
        if(ed<seg.first)
        {
            if(st!=-2e9) res.push_back({st,ed});
            st=seg.first;
            ed=seg.second;
        }
        else ed=max(ed,seg.second);
    }
    if(st!=-2e9) res.push_back({st,ed});
    segs=res;
}

int main()
{
    int n;
    cin>>n;
    int ans1=0,ans2=0;
    for(int i=0;i<n;i++)
    {
        int l,r;
        cin>>l>>r;
        segs.push_back({l,r});
    }
    merge(segs);
    for(int i=0;i<segs.size();i++)
    {
        ans1=max(ans1,segs[i].second-segs[i].first);
        if(i==0) ans2=0;
        else ans2=max(ans2,segs[i].first-segs[i-1].second);
    }
    cout<<ans1<<" "<<ans2<<endl;
    return 0;
}