【Hash】【二分查找】17.6.3 集合 题解

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <map>
#include <vector>
#define INF 92233720368546LL
#define LL long long

using namespace std;

const int maxx = 1e5 + 10, mod = 2e5;
int n, k, num = 0;
LL a[maxx];
map<LL, int> G;

struct Node {
int kill, cnt;
LL pos[2];
LL ber;
Node() { kill = cnt = ber = 0; }
bool operator < ( const Node &a ) const { return kill < a.kill; }
} b[maxx];

struct Ha {
vector<LL> ha[mod+10];
void Insert(LL x) {
int pos = x%mod;
for(int i = 0; i < ha[pos].size(); i++)
if(ha[pos][i] == x) return;
ha[pos].push_back(x);
}
int Find(LL x) {
int pos = x%mod;
for(int i = 0; i < ha[pos].size(); i++) if(ha[pos][i] == x) return 1;
return 0;
}
} L;

template <class T> inline void read(T &x) {
int flag = 1; x = 0;
char ch = getchar();
while(ch <  '0' || ch >  '9') { if(ch == '-')  flag = -1; ch = getchar(); }
while(ch >= '0' && ch <= '9') { x = (x<<1)+(x<<3)+ch-'0'; ch = getchar(); }
x *= flag;
}

inline void Unit() {
int col = a[1];
b[++num].cnt++;
b[num].ber = col;
for(int i = 2; i <= n; i++) {
if(col != a[i]) col = a[i], b[++num].ber = col;
b[num].cnt++;
}
}

int Binary_Find(LL x, int lft, int rgt, int Master) {
int mid = (lft+rgt)>>1;
if(lft == rgt) {
if(b[lft].ber != x) return 0;
b[Master].pos[b[Master].pos[0] ? 1 : 0] = b[lft].ber;
return b[lft].cnt;
}
if(b[mid].ber == x) {
b[Master].pos[b[Master].pos[0] ? 1 : 0] = b[mid].ber;
return b[mid].cnt;
}
return (x > b[mid].ber ? Binary_Find(x, mid+1, rgt, Master) : Binary_Find(x, lft, mid, Master));
}

inline void Static() {
for(int i = 1; i <= num; i++) {
if(!(b[i].ber%k)) b[i].kill += Binary_Find(b[i].ber/k, 1, num, i);
if(b[i].ber < INF) b[i].kill += Binary_Find(b[i].ber*k, 1, num, i);
}
}

inline int Select() {
int ans = 0;
sort(b+1, b+num+1);
for(int i = 1; i <= num; i++)
if(!L.Find(b[i].ber)) {
L.Insert(b[i].pos[0]);
L.Insert(b[i].pos[1]);
ans += b[i].cnt;;
}
return ans;
}

int main() {
freopen("set.in","r",stdin);
freopen("set.out","w",stdout);
read(n); read(k);
for(int i = 1, x; i <= n; i++) read(a[i]);
sort(a+1, a+n+1);
Unit();
Static();
printf("%d",Select());
return 0;
}