#include <bits/stdc++.h>
#define FOR(i,p,k) for(int i=(p);i<=(k);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define RFOR(i,p,n) for(int i=(p);i>=(n);--i)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define ssize(x) int((x).size())
#define fi first
#define se second
#define V vector
#define pb push_back
#define eb emplace_back
#define C const
#define gc getchar_unlocked
#define pc putchar_unlocked
#define pn putchar_unlocked('\n')
using namespace std;
typedef long long ll;
typedef __int128_t lll;
typedef V<int> vi;
typedef V<ll> vll;
typedef const int ci;
typedef const ll cll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<int, ll> pil;
void chmin(auto &a, auto b){a=min(a,b);}
void chmax(auto &a, auto b){a=max(a,b);}
ci inf = 2.1e9;
cll infll = 4.5e18;
int I(){
int z;
int c = gc();
while(c < '0' || c > '9') c = gc();
for(z = 0; c >= '0' && c <= '9'; c = gc()) z = 10*z+c-'0';
return z;
}
void O(int a){
static int tab[20];
int it = 0;
do{
tab[it++] = int('0'+a%10);
} while(a /= 10);
while(it) pc(tab[--it]);
}
mt19937 mt(691312137);
int los(ci a, ci b){
uniform_int_distribution<int> dist(a, b);
return dist(mt);
}
void answer(){
ci n = I();
ci q = I();
vi dzielpier(n+1, 0);
FOR(i, 2, n) if(!dzielpier[i]) for(int j = i; j <= n; j += i) dzielpier[j] = i;
vi kamien(n, 0);
vi xd;
V<pair<pii, int>> info;
int budzik = 0;
REP(_, q){
ci poz = I()-1;
if(kamien[poz] ^= 1) xd.eb(poz);
ci delta = kamien[poz] ? 1 : -1;
if(budzik == 0){
sort(all(xd));
xd.erase(unique(all(xd)), xd.end());
erase_if(xd, [&](ci i){return !kamien[i];});
V<pii> pary = {{2, 0}, {2, 1}};
auto rozroz = [&](ci a, ci b){
for(int x = abs(a-b); x > 1; x /= dzielpier[x]){
ci p = dzielpier[x];
pary.eb(p, a%p);
}
};
if(ssize(xd) <= 150){
for(int i = 0; i+2 < ssize(xd); i += 3){
rozroz(xd[i], xd[i+1]);
rozroz(xd[i], xd[i+2]);
rozroz(xd[i+1], xd[i+2]);
}
FOR(i, max(0, ssize(xd)-6), ssize(xd)-1){
FOR(j, i+1, ssize(xd)-1) rozroz(xd[i], xd[j]);
}
}
else{
REP(__, 150){
ci i = los(0, ssize(xd)-1);
ci j = los(0, ssize(xd)-1);
rozroz(xd[i], xd[j]);
}
}
sort(all(pary));
pary.erase(unique(all(pary)), pary.end());
info.clear();
for(auto [mod, resz] : pary){
int ile = 0;
for(ci i : xd) if(i%mod == resz) ++ile;
if(ile*3 >= ssize(xd)) info.eb(pii{mod, resz}, ile);
}
budzik = ssize(xd)/3;
}
else{
for(auto &[para, ile] : info) if(poz%para.fi == para.se) ile += delta;
--budzik;
}
int wyn = 0;
for(auto [para, ile] : info) chmax(wyn, ile);
O(wyn), pn;
}
}
int main(){
int tt = 1;
while(tt--) answer();
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | #include <bits/stdc++.h> #define FOR(i,p,k) for(int i=(p);i<=(k);++i) #define REP(i,n) FOR(i,0,(n)-1) #define RFOR(i,p,n) for(int i=(p);i>=(n);--i) #define all(x) (x).begin(),(x).end() #define rall(x) (x).rbegin(),(x).rend() #define ssize(x) int((x).size()) #define fi first #define se second #define V vector #define pb push_back #define eb emplace_back #define C const #define gc getchar_unlocked #define pc putchar_unlocked #define pn putchar_unlocked('\n') using namespace std; typedef long long ll; typedef __int128_t lll; typedef V<int> vi; typedef V<ll> vll; typedef const int ci; typedef const ll cll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef pair<ll, int> pli; typedef pair<int, ll> pil; void chmin(auto &a, auto b){a=min(a,b);} void chmax(auto &a, auto b){a=max(a,b);} ci inf = 2.1e9; cll infll = 4.5e18; int I(){ int z; int c = gc(); while(c < '0' || c > '9') c = gc(); for(z = 0; c >= '0' && c <= '9'; c = gc()) z = 10*z+c-'0'; return z; } void O(int a){ static int tab[20]; int it = 0; do{ tab[it++] = int('0'+a%10); } while(a /= 10); while(it) pc(tab[--it]); } mt19937 mt(691312137); int los(ci a, ci b){ uniform_int_distribution<int> dist(a, b); return dist(mt); } void answer(){ ci n = I(); ci q = I(); vi dzielpier(n+1, 0); FOR(i, 2, n) if(!dzielpier[i]) for(int j = i; j <= n; j += i) dzielpier[j] = i; vi kamien(n, 0); vi xd; V<pair<pii, int>> info; int budzik = 0; REP(_, q){ ci poz = I()-1; if(kamien[poz] ^= 1) xd.eb(poz); ci delta = kamien[poz] ? 1 : -1; if(budzik == 0){ sort(all(xd)); xd.erase(unique(all(xd)), xd.end()); erase_if(xd, [&](ci i){return !kamien[i];}); V<pii> pary = {{2, 0}, {2, 1}}; auto rozroz = [&](ci a, ci b){ for(int x = abs(a-b); x > 1; x /= dzielpier[x]){ ci p = dzielpier[x]; pary.eb(p, a%p); } }; if(ssize(xd) <= 150){ for(int i = 0; i+2 < ssize(xd); i += 3){ rozroz(xd[i], xd[i+1]); rozroz(xd[i], xd[i+2]); rozroz(xd[i+1], xd[i+2]); } FOR(i, max(0, ssize(xd)-6), ssize(xd)-1){ FOR(j, i+1, ssize(xd)-1) rozroz(xd[i], xd[j]); } } else{ REP(__, 150){ ci i = los(0, ssize(xd)-1); ci j = los(0, ssize(xd)-1); rozroz(xd[i], xd[j]); } } sort(all(pary)); pary.erase(unique(all(pary)), pary.end()); info.clear(); for(auto [mod, resz] : pary){ int ile = 0; for(ci i : xd) if(i%mod == resz) ++ile; if(ile*3 >= ssize(xd)) info.eb(pii{mod, resz}, ile); } budzik = ssize(xd)/3; } else{ for(auto &[para, ile] : info) if(poz%para.fi == para.se) ile += delta; --budzik; } int wyn = 0; for(auto [para, ile] : info) chmax(wyn, ile); O(wyn), pn; } } int main(){ int tt = 1; while(tt--) answer(); } |
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