Submission #1607743


Source Code Expand

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

#define rep(i,x,y) for(int i=(x);i<(y);++i)
#define debug(x) #x << "=" << (x)

#ifdef DEBUG
#define _GLIBCXX_DEBUG
#define print(x) std::cerr << debug(x) << " (L:" << __LINE__ << ")" << std::endl
#else
#define print(x)
#endif

const int inf=1e9;
const int64_t inf64=1e18;
const double eps=1e-9;

template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec){
    os << "[";
    for (const auto &v : vec) {
    	os << v << ",";
    }
    os << "]";
    return os;
}

using i64=int64_t;

string increment(string s){
    ++s[0];
    rep(i,0,s.size()-1) if(s[i]=='z'+1){
        ++s[i+1];
        s[i]='a';
    }
    if(s.back()=='z'+1){
        s.back()='a';
        s+="a";
    }
    return s;
}

void solve(){
    string A;
    cin >> A;

    static int min_index[200000][26];
    fill_n((int*)min_index,200000*26,inf);
    min_index[A.size()-1][A.back()-'a']=A.size()-1;
    for(int i=int(A.size())-2; i>=0; --i){
        rep(c,0,26) min_index[i][c]=min_index[i+1][c];
        min_index[i][A[i]-'a']=i;
    }

    static int memo[200001]={};
    static bool done[200001]={};

    function<int(int)> rec=[&](int index){
        int &res=memo[index];
        
        if(done[index]) return res;
        done[index]=true;

        if(index==A.size()) return res=1;
        
        int ma=0;
        rep(c,0,26) ma=max(ma,min_index[index][c]);
        if(ma==inf) return res=1;
        
        return res=rec(ma+1)+1;
    };

    function<void(int)> ans=[&](int index){
        int impossible_len=rec(index);

        if(impossible_len==1) rep(c,0,26) if(min_index[index][c]==inf){
            cout << char('a'+c) << endl;
            return;
        }

        rep(c,0,26){
            int index_=min_index[index][c]+1;
            if(rec(index_)==impossible_len-1){
                cout << char('a'+c);
                ans(index_);
                return;
            }
        }
    };

    ans(0);
}

int main(){
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    cout.setf(ios::fixed);
    cout.precision(16);
    solve();
    return 0;
}

Submission Info

Submission Time
Task E - Don't Be a Subsequence
User walkre
Language C++14 (GCC 5.4.1)
Score 600
Code Size 2217 Byte
Status AC
Exec Time 16 ms
Memory 22292 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 600 / 600
Status
AC × 3
AC × 36
Set Name Test Cases
Sample sample1.txt, sample2.txt, sample3.txt
All sample1.txt, sample2.txt, sample3.txt, 1.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 2.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, 25.txt, 26.txt, 27.txt, 28.txt, 29.txt, 3.txt, 30.txt, 4.txt, 5.txt, 6.txt, 7.txt, 8.txt, 9.txt, sample1.txt, sample2.txt, sample3.txt
Case Name Status Exec Time Memory
1.txt AC 7 ms 20608 KB
10.txt AC 15 ms 22036 KB
11.txt AC 15 ms 22036 KB
12.txt AC 15 ms 22036 KB
13.txt AC 15 ms 22036 KB
14.txt AC 15 ms 22036 KB
15.txt AC 15 ms 22036 KB
16.txt AC 15 ms 22036 KB
17.txt AC 15 ms 22036 KB
18.txt AC 15 ms 22164 KB
19.txt AC 16 ms 22164 KB
2.txt AC 7 ms 20608 KB
20.txt AC 15 ms 22292 KB
21.txt AC 15 ms 22292 KB
22.txt AC 15 ms 22292 KB
23.txt AC 15 ms 22292 KB
24.txt AC 14 ms 21908 KB
25.txt AC 13 ms 21396 KB
26.txt AC 13 ms 21012 KB
27.txt AC 13 ms 21012 KB
28.txt AC 13 ms 21012 KB
29.txt AC 13 ms 21012 KB
3.txt AC 8 ms 20608 KB
30.txt AC 13 ms 20884 KB
4.txt AC 8 ms 20608 KB
5.txt AC 11 ms 21328 KB
6.txt AC 11 ms 21328 KB
7.txt AC 15 ms 22036 KB
8.txt AC 15 ms 22036 KB
9.txt AC 15 ms 22036 KB
sample1.txt AC 7 ms 20608 KB
sample2.txt AC 7 ms 20608 KB
sample3.txt AC 7 ms 20608 KB