Submission #378352

#	Time	Username	Problem	Language	Result	Execution time	Memory
378352		soroush	Martian DNA (BOI18_dna)	C++17	100 / 100	75 ms	3308 KiB

dna

/*
#pragma GCC optimize("O2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,fma")
*/
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int , int> pii;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2e5 + 100;
const ll mod = 1e9+7;
const ld PI = acos((ld)-1);

#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define migmig ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}

int n , k , r;
int need[maxn];
int a[maxn];
int cnt[maxn];
int res = 0;

void add(int i){
	cnt[a[i]]++;
	if(cnt[a[i]] == 0)res--;
}

void rem(int i){
	if(cnt[a[i]] == 0)res++;
	cnt[a[i]]--;
}

bool chk(int k){
	bool ok = 0;
	for(int i = 1 ; i <= n ; i ++){
		add(i);
		if(i > k)rem(i - k);
		if(res == 0)ok = 1;
	}
	for(int i = n , j = 0 ; j < k ; i -- , j ++)rem(i);
	return(ok);
}

void prep(){
	for(int i = 1 ; i <= k ; i ++)
		cnt[i] = -need[i];
	for(int i = 1 ; i <= k ; i ++)
		res += (cnt[i] < 0);
}

int32_t main(){
	migmig;
	cin >> n >> k >> r;
	for(int i = 1 ; i <= n ; i ++)
		cin >> a[i] , a[i]++;
	for(int i = 1 ; i <= r ; i ++){
		int x , y;
		cin >> x >> y;
		need[x+1] = y;
	}	
	prep();
	int l = 0, r =  n + 1;
	while(r - l > 1){
		int mid = (l + r) / 2;
		if(chk(mid))
			r = mid;
		else
			l = mid;
	}
	if(r == n + 1)dokme("impossible");
	cout << r;
	return(0);
}

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 28 / 28
• Subtask 4: 32 / 32