Parco_Love_gcd

传送门

出题人说正解为RMQ，鄙人实在太蒟蒻了，不会呀只能暴力……

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define re register
const int N=1e6+10;
const int mod=1e9+7;
void read(int &a)
{
    a=0;
    int d=1;
    char ch;
    while(ch=getchar(),ch>'9'||ch<'0')
        if(ch=='-')
            d=-1;
    a=ch-'0';
    while(ch=getchar(),ch>='0'&&ch<='9')
        a=a*10+ch-'0';
    a*=d;
}
void write(int x)
{
    if(x<0)
        putchar(45),x=-x;
    if(x>9)
        write(x/10);
    putchar(x%10+'0');
}
int a[N];
int GCD(int a,int b)
{
    return b==0?a:GCD(b,a%b);
}
int main()
{
    int n;
    read(n);
    ll ans=0,gcd;
    read(a[0]);
    gcd=a[0];
    for(re int i=1;i<n;i++)
        read(a[i]),gcd=GCD(gcd,a[i]);
    for(re int i=0;i<n;i++)
    {
        int now=a[i];
        for(re int j=i;j<n;j++)
        {
            if(now==gcd)
            {
                ans=(ans+(n-j)*gcd)%mod;
                break;
            }
            now=GCD(now,a[j]);
            ans+=now;
            ans%=mod;
        }
    }
    write(ans);
    return 0;
}