914 - Jumping Champion uva

#include <bits/stdc++.h>
#define wrench786 ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ll long long
#define PI (acos(-1.0))
#define LIMIT 1000000
using namespace std;

vector<int>dum(1000001,0);
vector<int>prime;

void sieve(){
    int i,j;
    prime.push_back(2);
    for(i=3;i*i<=1000000;i+=2){
        if(!dum[i]){
            for(j=i*i;j<=1000000;j+=i){
                dum[j]=1;
            }
        }
    }
    for(i=3;i<=1000000;i+=2){
        if(!dum[i]) prime.push_back(i);
    }
}


int main(){
    wrench786

#ifndef ONLINE_JUDGE
    clock_t tStart = clock();
    freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#endif


    sieve();
    int n;
    cin>>n;
    while(n--){
        vector<int>vec(10000,0);
        int a,b,i,co=0,x,num;
        cin>>a>>b;
        for(i=0;prime[i]<=b;i++){
            if(prime[i]>=a && prime[i]<=b){
                if(co){
                    if(prime[i]-prime[i-1]>=0){
                        x = prime[i]-prime[i-1];
                        vec[x]++;
                    }
                }
                co++;
            }
        }
        x = *max_element(vec.begin(),vec.end());
        if(co==1 || co==0){
            cout<<"No jumping champion\n";
        }
        else{
            co=0;
            for(i=0;i<10000;i++){
                if(vec[i]==x){
                    num=i;
                    co++;
                }
            }
            if(co==1){
                cout<<"The jumping champion is "<<num<<"\n";
            }
            else{
                cout<<"No jumping champion\n";
            }
        }

    }
#ifndef ONLINE_JUDGE
    fprintf(stderr, "\n>> Runtime: %.10fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
#endif

}