Submission #1103998

#	Time	Username	Problem	Language	Result	Execution time	Memory
1103998		Luvidi	JJOOII 2 (JOI20_ho_t2)	C++17	0 / 100	1 ms	508 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fs first
#define sc second
#define pb push_back

void solve() {
    int n,k;
    cin>>n>>k;
    string s;
    cin>>s;
    int pre[n];
    int idx=0,cnt=0;
    for(int i=0;i<n;i++){
        cnt+=s[i]=='J';
        while(cnt-(s[idx]=='J')>=k){
            cnt-=s[idx]=='J';
            idx++;
        }
        if(cnt==k)pre[i]=i-idx+1-k;
        else pre[i]=1e9;
    }
    int suf[n];
    idx=n-1;
    cnt=0;
    for(int i=n-1;i>-1;i--){
        cnt+=s[i]=='I';
        while(cnt-(s[idx]=='I')>=k){
            cnt-=s[idx]=='I';
            idx--;
        }
        if(cnt==k)suf[i]=idx-i+1-k;
        else suf[i]=1e9;
    }
    int ans=1e9;
    idx=0;
    cnt=0;
    for(int i=0;i<n;i++){
        cnt+=s[i]=='O';
        while(cnt-(s[idx]=='O')>=k){
            cnt-=s[idx]=='O';
            idx++;
        }
        if(cnt==k){
            int x=i-idx+1-k;
            if(idx)x+=pre[idx-1];
            if(i<n-1)x+=suf[i+1];
            ans=min(ans,x);
        }
    }
    if(ans==1e9)ans=-1;
    cout<<ans;
}

int main() {
    #ifdef FPO
        freopen("in","r",stdin);
        freopen("out","w",stdout);
    #endif
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    solve();
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 12
• Subtask 3: 0 / 87