Submission #922729

#	Time	Username	Problem	Language	Result	Execution time	Memory
922729		vjudge1	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	10 ms	5668 KiB

ho_t2

#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

using namespace std;

#define ll long long
#define ld long double
#define pb push_back
#define pf push_front
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define F first
#define S second
#define mem(a,i) memset(a,i,sizeof(a))
#define sz(s) (int)s.size()
#define int ll
#define y1 yy
#define ppb pop_back
#define gcd(a,b) __gcd(a,b)
#define in insert

const int dx[4]={-1,0,1,0};
const int dy[4]={0,-1,0,1};

const int inf=1e9;
const int N=1e6;
const int MAX=2e5+10;
const int mod=1e9+7;

int n,k;
string s;
int nxt[MAX][3];

void calc(int tp,char x){
  int r=n;
  int cnt=0;
  for(int i=n;i>=1;i--){
    cnt+=(s[i]==x);
    while(cnt-(s[r]==x)>=k){
      cnt-=(s[r]==x);
      r--;
    }
    if(cnt<k)nxt[i][tp]=inf;
    else nxt[i][tp]=r;
  }
}

void solve(){
  cin>>n>>k;
  cin>>s;
  s="#"+s;
  calc(0,'J');
  calc(1,'O');
  calc(2,'I');
  int ans=inf;
  // cout<<nxt[4][1]<<" "<<nxt[7][2]<<"\n";
  for(int i=1;i<=n;i++){
    int r=nxt[i][0]+1;
    if(r>n)continue;
    r=nxt[r][1]+1;
    if(r>n)continue;
    r=nxt[r][2];
    if(r>n)continue;
    ans=min(ans,r-i+1-3*k);
  }
  if(ans!=inf)cout<<ans<<"\n";
  else cout<<-1<<"\n";
}

main(){
  // freopen("prizes.in", "r", stdin);
  // freopen("prizes.out", "w", stdout);
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t=1;
  // cin>>t;
  while(t--){
    solve();
  }
}

Compilation message (stderr)

ho_t2.cpp:72:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   72 | main(){
      | ^~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87