HDU 4777 樹狀數組求區間內 與該區間全互質的數個數

題意：

給定n個數的序列

m個詢問，問該區間內，與所有區間內數互質的數有多少個

#include
#include
#include
#include
#include
#define N 200005
using namespace std;
vectorprime[N];//prime[i] 是i的所有因子（不包括1）
vectoredge[N];
struct query{
	int l, r, num;
	bool operator<(const query& a)const{
		return a.l>l;
	}
}q[N];
int ans[N];

int tree[N];
int l[N], r[N], vis[N];
int n, m, a[N];

int lowbit(int x){return x&(-x);}
void add(int pos, int val){
	while(pos){
		tree[pos] += val;
		pos -= lowbit(pos);
	}
}
int getsum(int pos){
	int ans = 0;
	while(pos <= n){
		ans += tree[pos];
		pos += lowbit(pos);
	}
	return ans;
}

void init(){
	for(int i = 2; i < N; i++)
		for(int j = i; j < N; j+=i)
			prime[j].push_back(i);
}
int main(){
	int i, j;
	init();
	while(scanf("%d %d",&n,&m), n+m){
		for(i = 1; i <= n; i++)scanf("%d",&a[i]);

		memset(vis, 0, sizeof(vis));
		for(i = 1; i <= n; i++)
		{
			int pos = 0, siz = prime[a[i]].size();
			for(j = 0; j < siz; j++)
			{
				pos = max(pos, vis[prime[a[i]][j]]);
				vis[prime[a[i]][j]] = i;
			}
			l[i] = pos;
		}
		memset(vis, 1, sizeof(vis));
		for(i = n; i ; i--)
		{
			int pos = n+1, siz = prime[a[i]].size();
			for(j = 0; j < siz; j++)
			{
				pos = min(pos, vis[prime[a[i]][j]]);
				vis[prime[a[i]][j]] = i;
			}
			r[i] = pos;
		}

				memset(tree, 0, sizeof(tree));
		for(i = 1; i <= n; i++)
		{
			if(l[i])
				edge[l[i]].push_back(i);
			else
			{
				add(i, 1);
				if(r[i]<=n)
				add(r[i], -1);
			}
		}
		for(i = 1; i <= m; i++)scanf("%d %d",&q[i].l,&q[i].r), q[i].num = i;
		sort(q+1, q+m+1);
		int num = 1;
		for(i = 1; i <= n; i++)
		{
			while(q[num].l == i)
			{
				ans[q[num].num] = getsum(q[num].l) - getsum(q[num].r+1);
				num++;
			}
			add(i, -1);
			if(r[i] <= n)
			add(r[i], 1);
			for(j = 0; j < edge[i].size(); j++)
			{
				int v = edge[i][j];
				add(v, 1);
				if(r[v]<=n)
				add(r[v], -1);
			}
			edge[i].clear();
		}
		for(i = 1; i<= m; i++)printf("%d\n", ans[i]);
	}
	return 0;
}