[BZOJ2821]作诗(Poetize)

#include <cmath>
#include <cstdio>
#include <algorithm>
using namespace std;
inline int readint(){
    int n = 0;
    char ch = getchar();
    while(ch < ‘0‘ || ch > ‘9‘) ch = getchar();
    while(ch <= ‘9‘ && ch >= ‘0‘){
        n = (n << 1) + (n << 3) + ch - ‘0‘;
        ch = getchar();
    }
    return n;
}
const int maxn = 100000 + 10;
int n, c, m;
int a[maxn], belong[maxn], block_size;
int f[1500][1500], tax[maxn];
inline void work(int x){
    int ans = 0;
    for(int i = (x - 1) * block_size + 1; i <= n; i++) tax[a[i]] = 0;
    for(int i = (x - 1) * block_size + 1; i <= n; i++){
        tax[a[i]]++;
        if((tax[a[i]] & 1) && tax[a[i]] != 1) ans--;
        if(!(tax[a[i]] & 1)) ans++;
        f[x][belong[i]] = ans;
    }
}
struct Node{int pos, val;}no[maxn];
inline bool cmp(const Node &a, const Node &b){
    return a.val == b.val ? a.pos < b.pos : a.val < b.val;
}
int first[maxn], last[maxn];
inline int upper(int x, int k){
    int l = first[x], r = last[x], mid, ret = 0;
    while(l <= r){
        mid = l + r >> 1;
        if(no[mid].pos > k) r = mid - 1;
        else{
            ret = mid;
            l = mid + 1;
        }
    }
    return ret;
}
inline int lower(int x, int k){
    int l = first[x], r = last[x], mid, ret = 66662333;
    while(l <= r){
        mid = l + r >> 1;
        if(no[mid].pos < k) l = mid + 1;
        else{
            ret = mid;
            r = mid - 1;
        }
    }
    return ret;
}
inline int Count(int l, int r, int x){
    return max(upper(x, r) - lower(x, l) + 1, 0);
}
bool mark[maxn] = {false};
inline int Query(int l, int r){
    int ans = 0;
    if(belong[r] - belong[l] <= 1){
        for(int t, i = l; i <= r; i++){
            if(mark[a[i]]) continue;
            mark[a[i]] = true;
            t = Count(l, r, a[i]);
            if(!(t & 1) && t) ans++;
        }
        for(int i = l; i <= r; i++) mark[a[i]] = false;
        return ans;
    }
    else{
        int ll = belong[l] * block_size + 1, rr = (belong[r] - 1) * block_size;
        ans = f[belong[ll]][belong[rr]];
        for(int x, y, i = l; i < ll; i++){
            if(mark[a[i]]) continue;
            mark[a[i]] = true;
            x = Count(l, r, a[i]);
            y = Count(ll, rr, a[i]);
            if((x & 1)){
                if(!(y & 1) && y) ans--;
            }
            else if(x && (!y || (y & 1))) ans++;
        }
        for(int x, y, i = rr + 1; i <= r; i++){
            if(mark[a[i]]) continue;
            mark[a[i]] = true;
            x = Count(l, r, a[i]);
            y = Count(ll, rr, a[i]);
            if((x & 1)){
                if(!(y & 1) && y) ans--;
            }
            else if(x && (!y || (y & 1))) ans++;
        }
        for(int i = l; i < ll; i++) mark[a[i]] = false;
        for(int i = rr + 1; i <= r; i++) mark[a[i]] = false;
        return ans;
    }
}
int main(){
    n = readint();
    c = readint();
    m = readint();
    block_size = 1.0 * n / sqrt(log2(n + 1) * m);
    for(int i = 1; i <= n; i++) belong[i] = (i - 1) / block_size + 1;
    for(int i = 1; i <= n; i++){
        no[i].val = a[i] = readint();
        no[i].pos = i;
    }
    sort(no + 1, no + n + 1, cmp);
    for(int i = 1; i <= n; i++){
        if(!first[no[i].val]) first[no[i].val] = i;
        last[no[i].val] = i;
    }
    for(int i = 1; i <= n; i++) work(i);
    for(int l, r, ans = 0, i = 1; i <= m; i++){
        l = (readint() + ans) % n + 1;
        r = (readint() + ans) % n + 1;
        if(l > r) swap(l, r);
        printf("%d\n", ans = Query(l, r));
    }
    return 0;
}