HDU 4777 Rabbit Kingdom --容斥原理+树状数组

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
using namespace std;
#define N 200007

struct node{
    int l,r,ind;
    node(int _l,int _r,int _ind):l(_l),r(_r),ind(_ind){}
    node(){}
    bool operator<(const node &B)const{ return r<B.r; }
}Q[N];
vector<node> AB[3];
int ans[3][N],T[N];
int a[N],pos[N],maxi,L[N],R[N],n,m,c[N];

int cmp(node ka,node kb) { return ka.r < kb.r; }
int lowbit(int x) { return x&-x; }

void modify(int x)
{
    if(x <= 0) return;
    while(x <= n) { c[x]++; x += lowbit(x); }
}

int getsum(int x)
{
    int res = 0;
    while(x > 0) { res += c[x]; x -= lowbit(x); }
    return res;
}

void init()
{
    int i,j;
    for(i=0;i<=maxi;i++) pos[i] = 0;
    for(i=1;i<=n;i++)
    {
        int tmp = a[i];
        for(j=2;j*j<=tmp;j++)
        {
            if(tmp%j == 0)
            {
                L[i] = max(L[i],pos[j]);
                pos[j] = i;
                while(tmp%j == 0) tmp/=j;
            }
        }
        if(tmp != 1)
        {
            L[i]=max(L[i],pos[tmp]);
            pos[tmp]=i;
        }
    }
    for(i=0;i<=maxi;i++) pos[i] = n+1;
    for(i=n;i>=1;i--)
    {
        int tmp = a[i];
        for(j=2;j*j<=tmp;j++)
        {
            if(tmp%j == 0)
            {
                R[i] = min(R[i],pos[j]);
                pos[j] = i;
                while(tmp%j == 0) tmp/=j;
            }
        }
        if(tmp != 1)
        {
            R[i]=min(R[i],pos[tmp]);
            pos[tmp]=i;
        }
    }
}

void GET(int k)
{
    memset(c,0,sizeof(c));
    int i,j = 0;
    for(i=1;i<=m;i++)
    {
        int L = Q[i].l;
        int R = Q[i].r;
        int ind = Q[i].ind;
        while(j < n && AB[k][j].r <= R)
            modify(AB[k][j].l), j++;
        ans[k][ind] = getsum(R)-getsum(L-1);
    }
}

int main()
{
    int i,j;
    while(scanf("%d%d",&n,&m)!=EOF && n+m)
    {
        maxi = 0;
        memset(ans,0,sizeof(ans));
        for(i=0;i<3;i++) AB[i].clear();
        for(i=1;i<=n;i++)
        {
            scanf("%d",&a[i]), maxi = max(maxi,a[i]);
            L[i] = 0, R[i] = n+1;
        }
        init();
        for(i=1;i<=m;i++)
        {
            scanf("%d%d",&Q[i].l,&Q[i].r);
            Q[i].ind = i;
            T[i] = Q[i].r-Q[i].l+1;
        }
        sort(Q+1,Q+m+1);
        for(i=1;i<=n;i++)
        {
            AB[0].push_back(node(L[i],i,0));       //A : L[i]在区间内的数的个数
            AB[1].push_back(node(i,R[i],0));       //B : R[i]在区间内的数的个数
            AB[2].push_back(node(L[i],R[i],0));    //A交B
        }
        for(i=0;i<3;i++)
        {
            sort(AB[i].begin(),AB[i].end());
            GET(i);
        }
        for(i=1;i<=m;i++)
            printf("%d\n",T[i]-ans[0][i]-ans[1][i]+ans[2][i]);  //容斥原理
    }
    return 0;
}