题解 | 小红的gcd

#include <stdio.h>
#include <stdlib.h>
long long gcd(long long a,long long b){
    while(b!=0){
        int temp = b;
        b = a%b;
        a = temp;
    }
    return a;
}
long long a_gcd(long long a[],int n){
    long long res = a[0];
    for(int i = 0;i < n;i++){
        res = gcd(res,a[i]);
        if(res==1){
            break;
        }
    }
    return res;
}
int main() {
    int n;
    scanf("%d",&n);
    long long *a = (long long*)malloc(n*sizeof(long long));
    for(int i = 0;i < n;i++){
        scanf("%lld",&a[i]);
    }
    long long g = a_gcd(a,n);
    printf("%lld",g*n);
    free(a);
    return 0;
}