Codeforces Testing Round #12 B - Restaurant ( 贪心 )

#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define pb push_back
#define X first
#define Y second
#define cl(a,b) memset(a,b,sizeof(a))
typedef pair<int,int> P;
const int maxn=500005;
const int inf=1<<27;
P p[maxn];
int main(){
int n;
scanf("%d",&n);
for(int i=0;i<n;i++){
scanf("%d%d",&p[i].Y,&p[i].X);
}
sort(p,p+n);
int ans=1;
int t=p[0].X;
for(int i=1;i<n;i++){
if(p[i].Y>t){
t=p[i].X;
ans++;
}
}
printf("%d\n",ans);
return 0;
}