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  1. #include <bits/stdc++.h>
  2.  
  3. #define ll long long
  4. #define el cout << '\n'
  5.  
  6. using namespace std;
  7.  
  8. const int maxn = 1e5;
  9. const string AP = "0123456789ABCDEF";
  10.  
  11. int n, p[maxn + 10];
  12. string s;
  13.  
  14. int main()
  15. {
  16.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  17.     if (fopen("REKMP.INP", "r"))
  18.     {
  19.         freopen("REKMP.INP", "r", stdin);
  20.         freopen("REKMP.OUT", "w", stdout);
  21.     }
  22.  
  23.     cin >> n;
  24.     for (int i = 1; i <= n; i++)
  25.     {
  26.         cin >> p[i];
  27.     }
  28.     string s = " 0";
  29.     if (p[0])
  30.         return cout << -1, 0;
  31.     for (int i = 2; i <= n; i++)
  32.     {
  33. //        if (p[i])
  34. //        {
  35. //            if (p[i] != p[i - 1] + 1)
  36. //                return cout << -1, 0;
  37. //            s += s[p[i]];
  38. //        }
  39. //        else
  40. //        {
  41.             bool flag = 0;
  42.             for (char c : AP)
  43.             {
  44.                 int j = p[i - 1];
  45.                 while (j && s[j + 1] != c)
  46.                     j = p[j];
  47.                 if ((p[i] && s[j + 1] == c && p[i] == j + 1) || (!p[i] && s[j + 1] != c))
  48.                 {
  49.                     s += c;
  50.                     flag = 1;
  51.                     break;
  52.                 }
  53. //                    continue;
  54. //                if (j == 0)
  55. //                {
  56. //                    s += c;
  57. //                    flag = 1;
  58. //                    break;
  59. //                }
  60.             }
  61.             if (!flag)
  62.                 return cout << -1, 0;
  63. //        }
  64.     }
  65.     for (int i = 1; i < s.size(); i++)
  66.         cout << s[i];
  67. }
  68.  
Success #stdin #stdout 0s 5320KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/NjS0Tj
language:
C++14 (gcc 8.3)
created:
2 days ago
visibility:
public

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