找点（NYOJ891）

//#define LOCAL

#include<cstdio>

#include<iostream>

#include<cmath>

#include<algorithm>

int const MAX_N=101;

typedef struct Point{

    int x,y;

    bool operator<(const Point &other) const

    {

        return x<other.x;

    };

};

Point Vec[MAX_N];

int N,R,x,y;

void solve()

{

    int coun=0,i;

    for(i=0;i<N;i++)

    {

        scanf("%d%d",&Vec[i].x,&Vec[i].y);

    }

    std::sort(Vec,Vec+N);

    int sum=Vec[0].y;

    coun=1;

    for(i=1;i<N;i++)

    {

        if(sum<Vec[i].x)

        {

                coun++;

                sum=Vec[i].y;

        }

        else

        {

            if(sum>Vec[i].y)

            {

                sum=Vec[i].y;

            }

           }

    }

    printf("%d\n",coun);

}

int main()

{

#ifdef LOCAL

    freopen("891.in","r",stdin);

    freopen("891.out","w",stdout);

#endif

    while(~scanf("%d",&N))

    {

        solve();

    }

    return 0;

}