总结-莫队

常用技巧

• 奇偶优化

• \(\frac{n}{\sqrt{m}}\)

  普通莫队

LOJ6164「美团 CodeM 初赛 Round A」数列互质

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int a = (b); a <= (c); ++a)
#define nR(a,b,c) for(register int a = (b); a >= (c); --a)
#define Fill(a,b) memset(a, b, sizeof(a))
#define Swap(a,b) ((a) ^= (b) ^= (a) ^= (b))

#define ON_DEBUGG

#ifdef ON_DEBUGG

#define D_e_Line printf("\n-----------\n")
#define D_e(x) std::cout << (#x) << " : " <<x << "\n"
#define FileOpen() freopen("in.txt", "r", stdin)
#define FileSave() freopen("out.txt", "w", stdout)
#define Pause() system("pause")
#include <ctime>
#define TIME() fprintf(stderr, "\nTIME :　%.3lfms\n", clock() * 1000.0 / CLOCKS_PER_SEC)

#else

#define D_e_Line ;
#define D_e(x) ;
#define FileOpen() ;
#define FilSave ;
#define Pause() ;
#define TIME() ;

#endif

struct ios {
    template<typename ATP> ios& operator >> (ATP &x) {
        x = 0; int f = 1; char c;
        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-') f = -1;
        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
        x *= f;
        return *this;
    }
}io;

using namespace std;

template<typename ATP> inline ATP Min(ATP a, ATP b) {
    return a < b ? a : b;
}
template<typename ATP> inline ATP Max(ATP a, ATP b) {
    return a > b ? a : b;
}

#include <assert.h>

const int N = 50007;

int n, m;

struct Ques {
    int l, r, K, pos, id;
    bool operator < (const Ques &com) const {
        return pos != com.pos ? l < com.l : (pos & 1) ? r < com.r : r > com.r;
    }
} q[N];

int ans[N], a[N], tot[N], sum;
int appear[N];
int nxt[N], lst[N], st = -1;

inline void Add(int x) {
    if(x <= 0) return;
    if(!tot[x]){
        nxt[x] = st;
        if(st != -1) lst[st] = x;
        st = x, lst[x] = -1;
    }
    ++tot[x];
}

inline void Del(int x) {
    if(x <= 0) return;
    if(--tot[x]) return;
    assert(x >= 0);
    if(lst[x] != -1) nxt[lst[x]] = nxt[x];
    else st = nxt[x];
    if(nxt[x] != -1) lst[nxt[x]] = lst[x];
}

inline void Modify(int x, int w) {
    assert(a[x] >= 0);
    assert(x >= 0);
    Del(appear[a[x]]);
    appear[a[x]] += w;
    Add(appear[a[x]]);
}

inline int Gcd(int a, int b) {
    while(b ^= a ^= b ^= a %= b);
    return a;
}

int main() {
//FileOpen();
//FileSave();
    io >> n >> m;

    R(i,1,n){
        io >> a[i];
    }

    int blockSize = (int)sqrt((double)(n + 0.5));

    R(i,1,m){
        io >> q[i].l >> q[i].r >> q[i].K;
        q[i].pos = (q[i].l - 1) / blockSize + 1;
        q[i].id = i;
    }

    sort(q + 1, q + m + 1);

    int l = 1, r = 0;
    R(i,1,m){
        while(q[i].l < l) Modify(--l, 1);
        while(q[i].l > l) Modify(l++, -1);
        while(q[i].r > r) Modify(++r, 1);
        while(q[i].r < r) Modify(r--, -1);
        int sum = 0;
        for(register int j = st; ~j; j = nxt[j]){
            if(Gcd(j, q[i].K) == 1){
                assert(j >= 0);
                sum += tot[j];
            }
        }
        ans[q[i].id] = sum;
    }

    R(i,1,m){
        printf("%d\n", ans[i]);
    }

    return 0;
}