Submission #3878660

---

Source Code Expand

#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define sar(a,n) cout<<#a<<":";rep(pachico,n)cout<<" "<<a[pachico];cout<<endl
#define svec(v) cout<<#v<<":";rep(pachico,v.size())cout<<" "<<v[pachico];cout<<endl
#define svecp(v) cout<<#v<<":";each(pachico,v)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl
#define sset(s) cout<<#s<<":";each(pachico,s)cout<<" "<<pachico;cout<<endl
#define smap(m) cout<<#m<<":";each(pachico,m)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_N = 100005;

string s;
int n, K, keta;

bool comp(string& a, string& b)
{
    if(len(a) < len(b)){
        return true;
    }else if(len(a) > len(b)){
        return false;
    }else{
        return a < b;
    }
}

bool possible(string& t)
{
    string nw;
    int cnt = 0;
    rep(i,n){
        nw.pb(s[i]);
        if(comp(t, nw)){
            nw.clear();
            cnt++;
            nw.pb(s[i]);
            if(comp(t, nw)){
                return false;
            }
        }
    }
    return (cnt <= K);
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> K;
    cin >> s;
    n = len(s);
    keta = (n+K) / (K+1);
    if(K == 0){
        cout << s << "\n";
        return 0;
    }
    if(K == 1){
        string x = s.substr(0,keta), y = s.substr(n-keta,keta);
        if(comp(x, y)){
            cout << y << "\n";
        }else{
            cout << x << "\n";
        }
        return 0;
    }
    vs ss;
    rep(i,n-keta+1){
        ss.pb(s.substr(i,keta));
    }
    sort(all(ss),comp);
    int l = -1, r = n-keta;
    while(r-l>1){
        int mid = (l+r)/2;
        if(possible(ss[mid])){
            r = mid;
        }else{
            l = mid;
        }
    }
    cout << ss[r] << "\n";
    return 0;
}

Submission Info

Judge Result