Submission #891039

#	Time	Username	Problem	Language	Result	Execution time	Memory
891039		Xiaoyang	Martian DNA (BOI18_dna)	C++17	100 / 100	55 ms	9676 KiB

dna

#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll;
 
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 1ll<<60
#define rep(i,a,b) for (ll i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
#define endl "\n"
void inc(ll &a,ll b) {a=(a+b)%mod;}
void dec(ll &a,ll b) {a=(a-b+mod)%mod;}
int prod(ll a,ll b) {return ll(a)*ll(b)%mod;}
int lowbit(ll x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}


const ll maxn=222222;
ll a[maxn];
ll need[maxn];
vector<pll>tmp;
ll cnt[maxn];
ll bad[maxn];
ll n,k,r;
bool check(ll len){
	memset(cnt,0,sizeof cnt);
	memset(bad,0,sizeof bad);
	ll amt=0;
	rep(i,1,len+1)cnt[a[i]]++;
	rep(i,0,k){
		if(cnt[i]<need[i]){
			bad[i]=1;
			amt++;
		}
	}
	if(amt==0)return 1;
	//cout<<endl;
	//rep(i,0,k)cout<<i<<" "<<cnt[i]<<endl;
	//rep(i,0,k)cout<<bad[i]<<" ";
	//debug(amt);
	rep(i,2,n+2-len){
		//debug(i+len-1);
		//cout<<"-------------"<<endl;
		cnt[a[i-1]]--;
		if(cnt[a[i-1]]<need[a[i-1]] and !bad[a[i-1]]){//debug(11);
			amt++;
			bad[a[i-1]]=1;
		}
		cnt[a[i+len-1]]++;
		if(cnt[a[i+len-1]]>=need[a[i+len-1]] and bad[a[i+len-1]]){//debug(22);
			amt--;
			bad[a[i+len-1]]=0;
		}
		//rep(i,0,k)cout<<i<<" "<<cnt[i]<<endl;
		//rep(i,0,k)cout<<bad[i]<<" ";
		//debug(amt);
		if(amt==0){
			//debug(i);
			//debug(i+len);
			return 1;
		}
	}
	return 0;
}
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	//freopen("i.txt","r",stdin);
	cin>>n>>k>>r;
	rep(i,1,n+1)cin>>a[i];
	rep(i,1,r+1){
		ll x,y;cin>>x>>y;
		tmp.pb(MP(x,y));
		need[x]=y;
	}
	if(!check(n)){
		cout<<"impossible"<<endl;
		return 0;
	}
	ll lo=1,hi=n;
	//bsta the length 
	while(lo<hi){
		ll mid=(lo+hi)>>1;
		if(check(mid))hi=mid;
		else lo=mid+1;
	}
	cout<<lo<<endl;
	return 0;
}

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