（待修莫队 没过！ 抽空在检查）Dynamic len(set(a[L:R])) UVA - 12345

#include <iostream>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <map>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#define MOD 2018
#define LL long long
#define ULL unsigned long long
#define Pair pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define _  ios_base::sync_with_stdio(0),cin.tie(0)
//freopen("1.txt", "r", stdin);
using namespace std;
const int maxn = 50004, INF = 0x7fffffff;
int n, m, pos[maxn], s[1000005], c[maxn], ans, t[maxn];
int qsz, csz;
struct node
{
    int l, r, t, id, res;
}Node[maxn];

void add(int l, int r, int t, int id)
{
    Node[id].l = l;
    Node[id].r = r;
    Node[id].t = t;
    Node[id].id = id;
}
int l = 1, r = 0, T = 0;
struct change
{
    int pos, Old, New;
}Cha[maxn];

void add_(int pos, int New, int Old, int cnt)
{
    Cha[cnt].pos = pos;
    Cha[cnt].New = New;
    Cha[cnt].Old = Old;
}

bool cmp(node a, node b)
{
    if(pos[a.l] == pos[b.l])
    {
        if(pos[a.r] == pos[b.r])
            return a.t < b.t;
        return pos[a.r] < pos[b.r];
    }
    return pos[a.l] < pos[b.l];
}

bool cmp_id(node a, node b)
{
    return a.id < b.id;
}

void ad(int val)
{
    s[val]++;
    if(s[val] == 1)
        ans++;
}

void de(int val)
{
    s[val]--;
   // cout<< ans <<endl;
    if(s[val] == 0)
        ans--;
}

void go(int idx, int val)
{
    if(l <= idx && idx <= r)
    {
        de(c[idx]);
        ad(val);
    }
    c[idx] = val;
}

int main()
{
    qsz = csz = 0;
    ans = 0;
    scanf("%d%d", &n, &m);
    for(int i=1; i<=n; i++)
    {
        scanf("%d", &c[i]);
        t[i] = c[i];
    }
    int block = pow(n, 2.0/3);
    for(int i=1; i<=n; i++)
        pos[i] = (i-1)/block + 1;
    for(int i=1; i<=m; i++)
    {
        char str[5];
        int x, y;
        scanf("%s%d%d", str, &x, &y);
        if(str[0] == ‘Q‘)
        {
            add(++x, y, csz, ++qsz);
        }
        else
        {
            add_(++x, y, t[x], ++csz);
            t[x] = y;
        }
    }
    sort(Node+1, Node+1+qsz, cmp);
//    for(int i=1; i<=qsz; i++)
//        cout<< Node[i].l << "  " << Node[i].r << endl;
    for(int i=1; i<=qsz; i++)
    {
        for(; T < Node[i].t; T++)
            go(Cha[T+1].pos, Cha[T+1].New);
        for(; T > Node[i].t; T--)
            go(Cha[T].pos, Cha[T].Old);

        for(; r < Node[i].r; r++)
            ad(c[r+1]);
        for(; r > Node[i].r; r--)
            de(c[r]);
        for(; l < Node[i].r; l++)
            de(c[l]);
        for(; l > Node[i].l; l--)
            ad(c[l-1]);
//        for(; T < Node[i].t; T++)
//            go(Cha[T+1].pos, Cha[T+1].New);
//        for(; T > Node[i].t; T--)
//            go(Cha[T].pos, Cha[T].Old);

        Node[i].res = ans;
    }
    sort(Node+1, Node+qsz+1, cmp_id);
    for(int i=1; i<=qsz; i++)
        printf("%d\n",Node[i].res);

    return 0;
}

原文地址：https://www.cnblogs.com/WTSRUVF/p/9348152.html