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  1. #include <iostream>
  2. #include <string>
  3. #include <algorithm>
  4. using namespace std;
  5.  
  6. int findpali(string s, int dp[][100], int st, int e);
  7. int main(void)
  8. {
  9.     string s = "ABCD";
  10.     int dp[100][100];
  11.     for (int i = 0; i < 100; i++)
  12.         for (int j = 0; j < 100; j++)
  13.             dp[i][j] = -1;
  14.     int out = findpali(s, dp, 0, s.length() - 1);
  15.     cout << out << "\n";
  16.     return 0;
  17. }
  18.  
  19.  
  20.  
  21. int findpali(string s, int dp[][100], int st, int e) // st ->starting position, e -> ending position
  22. {
  23.     size_t length = s.length();
  24.     if (st < 0 || st >= length || e < 0 || e >= length)
  25.         cout << "This is trouble!!" << "  st = " << st << "  e = " << e << "  but s has length " << length << "\n";
  26.     if (s.length() == 1)
  27.     {
  28.         dp[st][e] = 1;
  29.         return 1;
  30.     }
  31.     else if (s.length() == 2 && s[st] == s[e])
  32.     {
  33.         dp[st][e] = 2;
  34.         return 2;
  35.     }
  36.     else if (dp[st][e] != -1)
  37.         return dp[st][e];
  38.     else if (s[st] == s[e])
  39.     {
  40.         dp[st][e] = findpali(s.substr(st + 1, s.length() - 2), dp, st + 1, e - 1) + 2;
  41.         return dp[st][e];
  42.     }
  43.     else
  44.     {
  45.         dp[st][e] = max(findpali(s.substr(st, s.length() - 1), dp, st, e - 1), findpali(s.substr(st + 1, s.length() - 1), dp, st + 1, e));
  46.         return dp[st][e];
  47.     }
  48. }
Runtime error #stdin #stdout #stderr 0s 3464KB
comments (?)
stdin 
Standard input is empty
stdout 
This is trouble!!  st = 1  e = 3  but s has length 3
This is trouble!!  st = 2  e = 3  but s has length 1
This is trouble!!  st = 1  e = 2  but s has length 2
This is trouble!!  st = 2  e = 2  but s has length 0
stderr 
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 3) > this->size() (which is 0)
https://ideone.com/1CGnT5
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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