Prime Distance UVA - 10140

#include<iostream>
#include <algorithm>
#include <cstring>
using namespace std;
 
 const int M=1e6+10;
 #define int long long 
 int P[M],fac[M],tot;
 int b[M];
 int bin[M],B;
 
 void init(int top){
 	int i,j; for(i=2;i<=top;i++) P[i]=1;
 	P[0]=P[1]=0;
 	
	for(i=2;i<=top;i++){
		if(P[i]==0)  continue;
		fac[++tot]=i;
		for(j=i*2;j<=top;j+=i) P[j]=0; 
	} 
 }
 int L,R;
 void sov(){
 	int i,j;
 	memset(b,0,sizeof b);
 	if(L==1){
 		b[0]=1;
 	}
 	for(i=1;i<=tot;i++){
 		for(j=L/fac[i];j<=R/fac[i];j++)
 		 if(j>1)  b[j*fac[i]-L]=1;
 	}
 	B=0;
 	for(i=L;i<=R;i++)
 	 if(b[i-L]==0) bin[++B]=i;
 	
 	int t1=2147483647,t2=0; 
 	int x1,y1,x2,y2;
 	for(i=1;i<B;i++){
 		int t =bin[i+1]-bin[i];
 		if(t1>t){ x1=bin[i],y1=bin[i+1],t1=t; }
 		if(t2<t){ x2=bin[i],y2=bin[i+1],t2=t; }
 	}
 	if(t2==0) printf("There are no adjacent primes.\n");
 	else 
 	printf("%d,%d are closest, %d,%d are most distant.\n",
 	x1,y1,x2,y2);
 }
 signed main(){
 	init(6e4);
 	
 	while(cin>>L>>R) sov();
 }