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

string dao(string s) {
  string temp;
  for (int i=0; i<s.size(); i++) {
    temp+=s[s.size()-i-1];
  }
  return temp;
}
//TRAU: O(n^3)
/*int lientiep(string s) {
  int maxx=0;
  for (int i=0; i<s.size(); i++) {
    for (int j=i+1; j<s.size(); j++) {
      string temp=s.substr(i, j-i+1);
      if (dao(temp)==temp) {
        if (temp.size()>maxx) maxx=temp.size();
      }
    }
  }
  return maxx;
}*/

int lientiep(string s) {
  int maxx=0;
  bool c, l;
  int dc, dl;
  for (int i=1; i<s.size()-1; i++) {
    c=true;
    l=true;
    dc=0;
    dl=0;
    for (int j=1; j<s.size(); j++) {
      if (c) {
        if (s[i-dc]==s[j]) dc++;
        else c=false;
      }
      if (l) {
        if (s[i-j]==s[j]) dl++;
        else l=false;
      }
      if (c==false && l==false) break;
    }
    if (dc>maxx) maxx=dc;
    if (dl>maxx) maxx=dl;
  }
  return maxx;
}

int khonglientiep(string s) {
  string p=dao(s);
  int dp[s.size()+1][s.size()+1];
  for (int i=1; i<=s.size(); i++) {
    dp[0][i]=dp[i][0]=0;
  }
  for (int i=1; i<=s.size(); i++) {
    for (int j=1; j<=s.size(); j++) {
      if (s[i-1]=p[j-1]) dp[i][j]=dp[i-1][j-1]+1;
      else dp[i][j]=max(dp[i-1][j], dp[i][j-1]);    
    }
  }
  return dp[s.size()+1][s.size()+1];
}

int main() 
{
    string s;
    getline(cin, s);
    cout << lientiep(s) << endl;
    cout << khonglientiep(s);
    return 0;
}
by

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}