CF 1459 C. Row GCD

http://codeforces.com/contest/1459/problem/C

根据辗转相减法 gcd(a,b)=gcd(b,a-b) 

gcd(a1+b,a2+b,a3+b,……,an+b)=gcd(a1+b,a2-a1,a3-a1,……,an-a1)

#include<cstdio> 
#include<algorithm>
 
using namespace std;
 
#define N 200001
 
typedef long long LL;
 
LL a[N],b[N];
 
LL gcd(LL a,LL b) 
{
    return !b ? a : gcd(b,a%b); 
}
 
int main()
{
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i) scanf("%lld",&a[i]);
    for(int i=1;i<=m;++i) scanf("%lld",&b[i]);
    LL g=0;
    for(int i=2;i<=n;++i) g=gcd(abs(a[i]-a[1]),g);
    for(int i=1;i<=m;++i) printf("%lld ",gcd(a[1]+b[i],g));
    
}