51nod 1133 不重叠的线段

#include <bits/stdc++.h>using namespace std;struct line{long long st,ed;}arr[10010];bool cmp(line l1,line l2){if(l1.ed!=l2.ed)return l1.ed<l2.ed;return l1.st<l2.st;} int main(){long long n,i,ans,now;while(cin>>n){for(i=1;i<=n;i++){scanf("%lld%lld",&arr[i].st,&arr[i].ed);}sort(arr+1,arr+n+1,cmp);ans=0;now=-(1<<30);for(i=1;i<=n;i++){if(arr[i].st>=now){now=arr[i].ed;ans++;}}printf("%lld\n",ans);}}