Submission #1792021


Source Code Expand

#include <cstdio>
#include <climits>
#include <cassert>
#include <cmath>
#include <iostream>
#include <string>
#include <algorithm>
#include <numeric>
#include <functional>
#include <tuple>
#include <list>
#include <map>
#include <queue>
#include <stack>
#include <set>
#include <vector>

#define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++)
#define FOR(x,xs) for(auto &x: xs)

using namespace std;
typedef long long ll;
typedef pair<int,int> PI;
typedef pair<ll,ll> PL;
typedef vector<int> VI;
typedef vector<ll> VL;

const int M = 26;

int main() {
  ios::sync_with_stdio(false);
  string a;
  cin >> a;
  int n = a.size();
  VI sep;
  vector<bool> app(M, false);
  int appcount = 0;
  vector<VI> pos(M);
  for(int i = n-1; i >= 0; i--) {
    if(!app[a[i]-'a']) {
      app[a[i]-'a'] = true;
      appcount++;
      if(appcount == M) {
        sep.push_back(i);
        app.assign(M, false);
        appcount = 0;
      }
    }
  }
  if(sep.empty()) {
    REP(i,0,M) {
      if(!app[i]) {
        cout << (char)('a'+i) << endl;
        return 0;
      }
    }
  }
  reverse(sep.begin(), sep.end());
  sep.push_back(n);
  REP(i,0,n) {
    pos[a[i]-'a'].push_back(i);
  }
  int len = sep.size();
  int used = -1;
  string ans;
  REP(i,0,len) {
    REP(c,0,M) {
      auto cp = lower_bound(pos[c].begin(), pos[c].end(), used);
      if(cp == pos[c].end() || *cp >= sep[i]) {
        ans.push_back('a' + c);
        used = *cp + 1;
        break;
      }
    }
  }
  cout << ans << endl;
  
  return 0;
}

Submission Info

Submission Time
Task E - Don't Be a Subsequence
User minus3theta
Language C++14 (GCC 5.4.1)
Score 600
Code Size 1583 Byte
Status AC
Exec Time 5 ms
Memory 1428 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 1 ms 256 KB
10.txt AC 5 ms 1428 KB
11.txt AC 5 ms 1428 KB
12.txt AC 5 ms 1428 KB
13.txt AC 5 ms 1428 KB
14.txt AC 5 ms 1428 KB
15.txt AC 5 ms 1428 KB
16.txt AC 5 ms 1428 KB
17.txt AC 5 ms 1428 KB
18.txt AC 5 ms 1428 KB
19.txt AC 5 ms 1428 KB
2.txt AC 1 ms 256 KB
20.txt AC 4 ms 1428 KB
21.txt AC 4 ms 1428 KB
22.txt AC 4 ms 1428 KB
23.txt AC 4 ms 1428 KB
24.txt AC 4 ms 1300 KB
25.txt AC 3 ms 1428 KB
26.txt AC 3 ms 1428 KB
27.txt AC 3 ms 1428 KB
28.txt AC 3 ms 1428 KB
29.txt AC 3 ms 1428 KB
3.txt AC 1 ms 384 KB
30.txt AC 3 ms 1428 KB
4.txt AC 1 ms 384 KB
5.txt AC 3 ms 848 KB
6.txt AC 3 ms 848 KB
7.txt AC 5 ms 1428 KB
8.txt AC 5 ms 1428 KB
9.txt AC 5 ms 1428 KB
sample1.txt AC 1 ms 256 KB
sample2.txt AC 1 ms 256 KB
sample3.txt AC 1 ms 256 KB