使用C++ 类

#include <iostream>
#include <algorithm>

using namespace std;

const int N = 100010;
int res;

class range {
public:
    int l, r;
    range(int left = 0, int right = 0) : l(left), r(right) {}

    bool operator<(const range &A)
    {
        return r < A.r;
    }
    void init(int left, int right)
    {
        l = left;
        r = right;
    }
};
range rec[N];

int main ()
{
    int n, l, r;
    scanf ("%d", &n);
    for (int i = 0; i < n; i ++)
    {
        scanf("%d%d", &l, &r);
        rec[i].init(l, r);
    }
    sort (rec, rec + n);
    int ed =  -2e9;
    for (int i = 0; i < n; i ++)
    {
        if (rec[i].l > ed)  
        {
            res ++;
            ed = rec[i].r;
        }
    }

    printf("%d", res);
    return 0;
}