Question

This is for C++
A string is a palindrome if reverse of the string is same as the original string. For example, “abba” is palindrome, but “abbc” is not palindrome. Basically a string with a plane of symmetry in the middle of it is considered a palindrome. For example, the following strings are palindromic: "abbbbba", "abba", "abbcbba", "a", etc. For this problem, you have an input string consisting of both lowercase or uppercase characters. You are allowed to pick and chose any of the characters from the input to construct a new string palindrome. What is the length of the longest palindrome you can construct?

Write a function that takes any arbitrary string, str, to obtain the length of the longest palindrome. You MUST make use of the following function signature:

input: "aBc"

output: 1

Explanation: you can take any single character as a palindrome. The longest one cannot go beyond 2 characters in this example because there are no duplicates.

input: "a"

output: 1  

Explanation: the input is a palindrome

  

input: "BAA"

output: 3

Explanation: the longest one you can construct is "ABA" which has 3 characters.

CONSTRAINTS/ASSUMPTIONS

• Input str is not empty or NULL.
• 1 < str.length() < 1000
• Input str has a combination of upper and lowercase characters.
• Uppercase and lowercase characters are not considered the same character in the context of building a string palindrome.
• Failure to follow the exact function signature will result in non-compilable code; resubmission policy ensues.

Answer 1

#include<bits/stdc++.h>

using namespace std;

int getlongestlength(string str)

{

int n = str.size();

int a[26][2]={0};

for(int i=0;i<n;i++)

{

if((str[i]<='z')&&(str[i]>='a'))

a[str[i]-'a'][0]++;

else

a[str[i]-'A'][1]++;

}

int length=0;

int odd=0;

for(int i=0;i<26;i++)

{

length +=a[i][0]/2+a[i]a[1]/2;

if((a[i][0]%2==1)||(a[i][1]%2==1))

odd=1;

}

length=2*length+odd;

return length;

}

int main()

{

cout<<getlongestlength("BBA");

return 0;

}

// i hope it is helpful for you