很简单的树状数组，又不是线段树，你们应该愿意看吧（

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e6 + 7;

int n, m;

struct Bit{
	#define lb(i) (i & -i)
	int t[MAXN];
	
	void modify(int x, int y) {
		for (; x <= n; x += lb(x)) t[x] += y;
	}
	int querydd(int x) {
		int ans = 0;
		for (; x; x -= lb(x)) ans += t[x];
		return ans;
	}
	int query(int x, int y) {return querydd(y) - querydd(x - 1); }
}t;

struct Node {
	int l, r;
	bool operator < (const Node other) const {
		return r < other.r;
	}
}A[MAXN];

int B[MAXN], Last[MAXN];//前一个数的下标

int V[MAXN], Ans[MAXN];

int main () {
	cin >> n;
	for (int i = 1; i <= n; i ++) cin >> B[i];
	cin >> m;
	for (int i = 1; i <= m; i ++) cin >> A[i].l >> A[i].r, V[A[i].r] = i;
	sort(A + 1, A + 1 + m);
	for (int i = 1; i <= n; i ++) {
		if (Last[B[i]] != 0) t.modify(Last[B[i]], -1); 
		Last[B[i]] = i; t.modify(Last[B[i]], 1);
		if (V[i]) Ans[V[i]] = t.query(A[V[i]].l, A[V[i]].r);
	}
	for (int i = 1; i <= m; i ++) cout << Ans[i] << '\n';
	return 0;
}

实在不行提供hack也行，蟹蟹你们啦