Submission #320623

#	Time	Username	Problem	Language	Result	Execution time	Memory
320623		teehandsome	JJOOII 2 (JOI20_ho_t2)	C++11	100 / 100	11 ms	2160 KiB

ho_t2

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define INF 1e9+7
#define all(x) x.begin(),x.end()
using namespace std;
using namespace __gnu_pbds;
using ll=long long;
using pii=pair<int,int>;
using ppi=pair<int,pii>;
using oset=tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>;

template<typename T>
void _print(vector<T> x) {for(auto e:x) cerr<<e<<",";}
template<typename T>
void _print(T x) {cerr<<x;}

void dbg() {cerr<<endl;}
template<typename Head,typename... Tail>
void dbg(Head H,Tail... T) {
    _print(H);
    if(sizeof...(T)) cerr<<",";
    else cerr<<"\"]";
    dbg(T...);
}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:[\"",dbg(__VA_ARGS__)

int n,k;
string s;

int main () {
    ios::sync_with_stdio(false); cin.tie(0);
    cin>>n>>k>>s;
    vector<int> J,O,I;
    for(int i=0;i<n;i++) {
        if(s[i]=='J') J.push_back(i);
        else if(s[i]=='O') O.push_back(i);
        else I.push_back(i);
    }
    int j_len=J.size(),o_len=O.size(),i_len=I.size();
    if(j_len<k or o_len<k or i_len<k) {
        cout<<"-1"<<endl; return 0;
    }
    int ans=INF;
    //debug(J); debug(O); debug(I);
    for(int i=0;i<o_len-k+1;i++) {
        int first_O=O[i];
        int last_O=O[i+k-1];
        int pos1_I=lower_bound(all(I),last_O)-begin(I);
        if(I[pos1_I]<last_O or pos1_I+k>i_len) continue;
        int last_all=I[pos1_I+k-1];
        int pos2_J=lower_bound(all(J),first_O)-begin(J)-1;
        if(pos2_J<k-1 or J[pos2_J]>first_O) continue;
        int first_all=J[pos2_J-k+1];
        ans=min(ans,last_all-first_all-3*k+1);
    }

    if(ans==INF) cout<<"-1"<<endl;
    else cout<<ans<<endl;
}

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