bzoj2301

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莫比乌斯反演+分块优化

PoPoQQQ的课件讲得很详细，大赞~！

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#include<map>#include<stack>#include<queue>#include<ctime>#include<cmath>#include<string>#include<cstdio>#include<cstdlib>#include<cstring>#include<utility>#include<iostream>#include<algorithm>const int SIZE = 50005;int mu[SIZE], prime[SIZE>>3], tot;bool check[SIZE];  int sum[SIZE];void PreWork(){    sum[1] = mu[1] = 1;    for(int i = 2; i < SIZE; i++)       {        if(!check[i]) prime[++tot] = i, mu[i] = -1;        sum[i] = sum[i-1] + mu[i];        for(int j = 1, t; j <= tot && (t = prime[j]*i) < SIZE; j++)        {            check[t] = true;            if(i%prime[j]) mu[t] = -mu[i];            else {mu[t] = 0; break;}        }    }   }long long Count(int p,int q){//  gcd(i,j)=1 [1,p] [1,q]    long long ret = 0;    if(p > q) std::swap(p,q);    for(int i = 1, next = 0; i <= p; i = next+1)    {        next = std::min(p/(p/i), q/(q/i));        ret += (long long)(sum[next]-sum[i-1])*(p/i)*(q/i);    }    return ret;}int main(){    int n;#ifndef ONLINE_JUDGE    freopen("bzoj2301.in","r",stdin);    freopen("bzoj2301.out","w",stdout);#endif    scanf("%d",&n);    PreWork();    while(n--)    {        int a, b, c, d, k;long long ans;        scanf("%d%d%d%d%d",&a,&b,&c,&d,&k);        ans = Count(b/k,d/k) - Count(b/k,(c-1)/k) - Count((a-1)/k,d/k) + Count((a-1)/k,(c-1)/k);        printf("%lld\n",ans);     }#ifndef ONLINE_JUDGE    fclose(stdin);    fclose(stdout);#endif    return 0；}