Spoj database

//http://www.spoj.com/problems/RPLD/

#include <cstdio>
#include <algorithm>
using namespace std;

pair< long int, long int > ar[100000];

inline bool comp(const pair< int, int > &a, const pair< int, int > &b) {
return (a.first == b.first) ? a.second < b.second : a.first < b.first;
}

int main() {
long int t, i, n, l,r,c=1,u;
scanf("%ld", &t);
while(t--) {
u=0;
scanf("%ld %ld", &r,&n);
for(i = 0; i < n; i++)
scanf("%ld %ld", &ar[i].first, &ar[i].second);
sort(ar, ar + n, comp);
for(i=0;i<n;i++){
if(ar[i].first==ar[i+1].first){
if(ar[i].second==ar[i+1].second){
u=1;
break;
}
}
}
if(u==1){
printf("Scenario #%ld: impossible\n",c);
}else{
printf("Scenario #%ld: possible\n",c);
}
c++;
}
return 0;
}