题目链接：区间选点

#include <iostream>
#include <algorithm>

using namespace std;

const int N = 100010;

int n;

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

int main()
{
    scanf("%d", &n);
    
    for(int i = 0; i < n; i ++)
    {
        int l, r;
        scanf("%d%d", &l, &r);
        range[i] = {l, r};
    }
    
    sort(range, range + n);
    
    // res: 当前选择的点的数量 ed: 上一个点的下标
    int res = 0, ed = -2e9;
    for(int i = 0; i < n; i ++)
        if(range[i].l > ed)
        {
            res ++;
            ed = range[i].r;
        }
        
    cout << res << endl;
    
    return 0;
}