hdu more than school sixth 1008 (hdu6641) TDL violence

Meaning of the questions:

Set F (n, m) is larger than n, and m-th prime number n, given a k = (f (n, m) -n) xor n and m, find the smallest n

answer:

For a given m, the a k around n legitimate distribution very dense, so violent k neighborhood search.

#include<iostream>
#define LL long long
using namespace std;
LL gcd(LL a,LL b){
    return b==0?a:gcd(b,a%b);
} 
bool solve(LL n,LL k,int m){
    //找到n后面的第m个互质
    register LL i;
    for(i=n+1;;i++){
        if(gcd(i,n)==1)m--;
        if(m==0)break;
    } 
    if(((i-n)^n)==k){
//        printf("%lld",i);
        return 1;
    }
    else return 0;
}
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        LL k;
        int m;
        scanf("%lld %d",&k,&m);
        for(register LL i=max(1ll,k-3000);i<=k+3000;i++){
            if(solve(i,k,m)){
                printf("%lld\n",i);
                goto A;
            }
        }
        printf("-1\n");
        A:;
    }
}