重铸华农荣光 我辈义不容辞

Day 27 - greedy algorithm

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

const int N=100010;
int n;

struct Range{
    int l,r;
    bool operator <(const Range & W)
    {
        return r<W.r;
    }
}range[N];

int main()
{
    cin>>n;
    for(int i=0;i<n;i++)
    {
        int l,r;
        cin>>l>>r;
        range[i]={l,r};
    }

    sort(range,range+n);

    int ans=0,ed=-2e9;
    for(int i=0;i<n;i++)
    {
        if(range[i].l>ed)
        {
            ans++;
            ed=range[i].r;
        }
    }

    cout<<ans;
    return 0;
}