2016 Multi-University Training Contest 1 GCD HDU - 5726

Give you a sequence of N(N≤100,000) integers : a1,…,an(0

#include<iostream>
#include<cstdio>
#include<map>
#include<algorithm>
#include<cstring>
#include<string>
using namespace std;
#define maxn 2000005
typedef long long ll;
#define inf 0x3f3f3f3f


inline int read()
{
    int x = 0, k = 1; char c = getchar();
    while (c < '0' || c > '9') { if (c == '-')k = -1; c = getchar(); }
    while (c >= '0' && c <= '9')x = (x << 3) + (x << 1) + (c ^ 48), c = getchar();
    return x * k;
}

ll gcd(ll a,ll b)
{
    return b==0?a:gcd(b,a%b);
}

ll a[maxn];
ll dp[maxn][21];
map<ll,ll>mp;


int init(int n)
{
    for(int i=0;i<n;i++)dp[i][0]=a[i];
    for(int j=1;(1<<j)<=n;j++){
        for(int i=0;i+(1<<j)-1<n;i++){
            dp[i][j]=gcd(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);
        }
    }
}

ll getGcd(int l,int r)
{
    int k=0;
    while((r-l+1)>=(1<<(k+1)))k++;
    return gcd(dp[l][k],dp[r-(1<<k)+1][k]);
}

int main()
{
    int n,q,l,m,t,r;
    t=read();int cnt=0;
    while(t--){
        cnt++;
        n=read();
        for(int i=0;i<n;i++){
            //a[i]=read();
            scanf("%lld",&a[i]);
        }
        init(n);
        mp.clear();
        for(int i=0;i<n;i++){
            int j=i;
            while(j<n){
                int ggcd=getGcd(i,j);
                l=j;r=n-1;
                while(l<r){
                    int mid=(l+r+1)>>1;
                    if(ggcd>getGcd(i,mid))r=mid-1;
                    else l=mid;
                }
                mp[ggcd]+=l-j+1;j=l+1;
            }

        }

        q=read();
        cout<<"Case #"<<cnt<<":"<<endl;
        while(q--){
            l=read();r=read();
            l--;r--;
            int ggcd=getGcd(l,r);
            cout<<ggcd<<' '<<mp[ggcd]<<endl;
        }
    }
}