Construct K Palindrome Strings in C++

C++Server Side ProgrammingProgramming

Suppose we have a string s and a number k. We have to construct k non-empty palindrome strings using all the characters in s. So here we have to check whether we can use all the characters in s to construct k palindrome strings or not.

So, if the input is like "true", k = 4, then the output will be True, as the only possible solution is to put each character in a separate string.

To solve this, we will follow these steps −

  • n := size of s

  • if n < k, then −

    • return false

  • if n is same as k, then −

    • return true

  • Define one map

  • for each character c in s

    • (increase m[c] by 1)

  • odd := 0

  • for each key-value pair it in m −

    • odd := odd + (value of it AND 1)

  • return true when odd <= k, otherwise false


Let us see the following implementation to get a better understanding −

 Live Demo

#include <bits/stdc++.h>
using namespace std;
class Solution {
   bool canConstruct(string s, int k) {
      int n = s.size();
      if (n < k)
         return false;
      if (n == k)
         return true;
      map<char, int> m;
      for (char c : s)
      int odd = 0;
      for (auto& it : m) {
         odd += (it.second & 1);
      return odd <= k;
   Solution ob;
   cout << (ob.canConstruct("true",4));




Published on 17-Nov-2020 11:32:11