Earlier we have discussed on how to check if both halves of the string have same set of characters. Now, we further extend our problem on checking if both halves of the string have at least one different character.
Examples:
Input : baaaab
Output: No, both halves do not differ at all
The two halves contain the same characters and their frequencies match so not different the character existsInput : abccpb
Output : Yes, both halves differ by at least one character
Method 1: (Two counter arrays)
- Split the string into two halves
- Traverse two different halves separately and count the occurrence of each character into two different counter array
- Now, traverse these arrays, and the if these array differ at a point, we get the answer as “Yes”
Implementation:
C++
// C++ implementation to check if // both halves of the string have // at least one different character #include <cstring> #include <iostream> #include <string> using namespace std; # define MAX 26 // Function which break string into two halves // Counts frequency of characters in each half // Compares the two counter array and returns // true if these counter arrays differ bool function(string str) { int l = str.length(); // Declaration and initialization // of counter array int counter1[MAX]; int counter2[MAX]; memset(counter1, 0, sizeof(counter1)); memset(counter2, 0, sizeof(counter2)); for (int i = 0; i < l / 2; i++) counter1[str[i] - 'a']++; for (int i = l / 2; i < l; i++) counter2[str[i] - 'a']++; for (int i = 0; i < MAX; i++) if (counter2[i] != counter1[i]) return true; return false; } // Driver function int main() { string str = "abcasdsabcae"; if (function(str)) cout << "Yes, both halves differ" <<" by at least one character"; else cout << "No, both halves do " <<"not differ at all"; return 0; } |
Java
// Java implementation of the problem import java.util.*; import java.lang.*; class neveropen { final static int MAX = 26; // Function which break string into two halves // Counts frequency of characters in each half // Compares the two counter array and returns // true if these counter arrays differ static boolean function(String str) { int l = str.length(); // Declaration and initialization // of counter array int counter1[] = new int[MAX]; int counter2[] = new int[MAX]; for (int i = 0; i < MAX; i++) { counter1[i] = 0; counter2[i] = 0; } for (int i = 0; i < l / 2; i++) counter1[str.charAt(i) - 'a']++; for (int i = l / 2; i < l; i++) counter2[str.charAt(i) - 'a']++; for (int i = 0; i < MAX; i++) { if (counter2[i] != counter1[i]) return true; } return false; } // Driver function public static void main(String args[]) { String str = "abcasdsabcae"; if (function(str)) System.out.print("Yes, both halves "+ "differ by at least one character"); else System.out.print("No, both halves "+ "do not differ at all"); } } |
Python3
# Python implementation to check if # both halves of the string have # at least one different character MAX = 26 # Function which break string into two halves # Counts frequency of characters in each half # Compares the two counter array and returns # true if these counter arrays differ def function(st): global MAX l = len(st) # Declaration and initialization # of counter array counter1, counter2 = [0] * MAX, [0] * MAX for i in range(l//2): counter1[ord(st[i]) - ord('a')] += 1 for i in range(l//2, l): counter2[ord(st[i]) - ord('a')] += 1 for i in range(MAX): if (counter2[i] != counter1[i]): return True return False # Driver function st = "abcasdsabcae"if function(st): print("Yes, both halves differ ", "by at least one character") else: print("No, both halves do not differ at all") # This code is contributed by Ansu Kumari |
C#
// C# implementation to check if // both halves of the string have // at least one different character using System; class neveropen { static int MAX = 26; // Function which break string into two halves // Counts frequency of characters in each half // Compares the two counter array and returns // true if these counter arrays differ static bool function(String str) { int l = str.Length; // Declaration and initialization // of counter array int []counter1 = new int[MAX]; int []counter2 = new int[MAX]; for (int i = 0; i < MAX; i++) { counter1[i] = 0; counter2[i] = 0; } for (int i = 0; i < l / 2; i++) counter1[str[i] - 'a']++; for (int i = l / 2; i < l; i++) counter2[str[i] - 'a']++; for (int i = 0; i < MAX; i++) { if (counter2[i] != counter1[i]) return true; } return false; } // Driver function public static void Main() { String str = "abcasdsabcae"; if (function(str)) Console.WriteLine("Yes, both halves "+ "differ by at least one character"); else Console.WriteLine("No, both halves "+ "do not differ at all"); } } //This code is contributed by vt_m. |
PHP
<?php // PHP implementation to check if // both halves of the string have // at least one different character $MAX = 26; // Function which break string into two halves // Counts frequency of characters in each half // Compares the two counter array and returns // true if these counter arrays differ function function_1($str) { global $MAX; $l = strlen($str); // Declaration and initialization // of counter array $counter1 = array_fill(0,$MAX,NULL); $counter2 = array_fill(0,$MAX,NULL); for ($i = 0; $i < $l / 2; $i++) $counter1[ord($str[$i]) - ord('a')]++; for ($i = $l / 2; $i < $l; $i++) $counter2[ord($str[$i]) - ord('a')]++; for ($i = 0; $i < $MAX; $i++) if ($counter2[$i] != $counter1[$i]) return true; return false; } // Driver function $str = "abcasdsabcae"; if (function_1($str)) echo "Yes, both halves differ" ." by at least one character"; else echo "No, both halves do " ."not differ at all"; return 0; ?> |
Javascript
<script> // JavaScript program implementation of the problem let MAX = 26; // Function which break string into two halves // Counts frequency of characters in each half // Compares the two counter array and returns // true if these counter arrays differ function functions(str) { let l = str.length; // Declaration and initialization // of counter array let counter1 = []; let counter2 = []; for (let i = 0; i < MAX; i++) { counter1[i] = 0; counter2[i] = 0; } for (let i = 0; i < l / 2; i++) counter1[str[i] - 'a']++; for (let i = l / 2; i < l; i++) counter2[str[i] - 'a']++; for (let i = 0; i < MAX; i++) { if (counter2[i] != counter1[i]) return true; } return false; } // Driver code let str = "abcasdsabcae"; if (functions(str) != 1) document.write("Yes, both halves "+ "differ by at least one character"); else document.write("No, both halves "+ "do not differ at all"); </script> |
Output
Yes, both halves differ by at least one character
Time Complexity: O(N), as we are using a loop to traverse N times. Where N is the length of the string.
Auxiliary Space: O(26), as we are using extra space for counter arrays.
Method 2:(One counter array)
- This method uses only a single array of length 26.
- For the first half, we increment the characters in the counter array of length 26.
- For second array, we decrement the character in that same counter array.
- Now, if for an index corresponding to a character has non-zero value, that is the distinct character present
- The positive ones are ones present in the first half and the negative ones are characters in the second half
Implementation:
C++
// C++ implementation to check if // both halves of the string have // at least one different character #include <cstring> #include <iostream> #include <string> using namespace std; # define MAX 26 // Function which break string into two halves // Increments frequency of characters for first half // Decrements frequency of characters for second half // true if any index has non-zero value bool function(string str) { int l = str.length(); // Declaration and initialization // of counter array int counter[MAX]; memset(counter, 0, sizeof(counter)); for (int i = 0; i < l / 2; i++) counter[str[i] - 'a']++; for (int i = l / 2; i < l; i++) counter[str[i] - 'a']--; for (int i = 0; i < MAX; i++) if (counter[i] != 0) return true; return false; } // Driver function int main() { string str = "abcasdsabcae"; if (function(str)) cout << "Yes, both halves differ" <<" by at least one character"; else cout << "No, both halves do" <<" not differ at all"; return 0; } |
Java
// Java implementation of the problem import java.util.*; import java.lang.*; class neveropen { final static int MAX = 26; // Function which break string into two halves // Increments frequency of characters for first half // Decrements frequency of characters for second half // true if any index has non-zero value static boolean function(String str) { int l = str.length(); // Declaration and initialization // of counter array int counter[] = new int[MAX]; for (int i = 0; i < MAX; i++) counter[i] = 0; for (int i = 0; i < l / 2; i++) counter[str.charAt(i) - 'a']++; for (int i = l / 2; i < l; i++) counter[str.charAt(i) - 'a']--; for (int i = 0; i < MAX; i++) if (counter[i] != 0) return true; return false; } // Driver function public static void main(String args[]) { String str = "abcasdsabcae"; if (function(str)) System.out.print("Yes, both halves" +" differ by at least one character"); else System.out.print("No, both halves" +" do not differ at all"); } } |
Python3
# Python3 implementation to check if # both halves of the string have # at least one different character MAX = 26 # Function which break string into two # halves Increments frequency of characters # for first half Decrements frequency of # characters for second half true if any # index has non-zero value def function(st): global MAX l = len(st) # Declaration and initialization # of counter array counter = [0] * MAX for i in range(l // 2): counter[ord(st[i]) - ord('a')] += 1 for i in range(l // 2, l): counter[ord(st[i]) - ord('a')] -= 1 for i in range(MAX): if (counter[i] != 0): return True return False # Driver function st = "abcasdsabcae"if function(st): print("Yes, both halves differ by at ", "least one character") else: print("No, both halves do not differ at all") # This code is contributed by Ansu Kumari |
C#
// C# implementation of the problem using System; class GFG { static int MAX = 26; // Function which break string into // two halves Increments frequency // of characters for first half // Decrements frequency of characters // for second half true if any index // has non-zero value static bool function(String str) { int l = str.Length; // Declaration and initialization // of counter array int []counter = new int[MAX]; for (int i = 0; i < MAX; i++) counter[i] = 0; for (int i = 0; i < l / 2; i++) counter[str[i] - 'a']++; for (int i = l / 2; i < l; i++) counter[str[i] - 'a']--; for (int i = 0; i < MAX; i++) if (counter[i] != 0) return true; return false; } // Driver function public static void Main() { string str = "abcasdsabcae"; if (function(str)) Console.Write("Yes, both halves" + " differ by at least one " + "character"); else Console.Write("No, both halves" + " do not differ at all"); } } // This code is contributed by anuj_67. |
Javascript
<script> // Javascript implementation of the problem let MAX = 26; // Function which break string into two halves // Increments frequency of characters for first half // Decrements frequency of characters for second half // true if any index has non-zero value function Function(str) { let l = str.length; // Declaration and initialization // of counter array let counter = new Array(MAX); for (let i = 0; i < MAX; i++) counter[i] = 0; for (let i = 0; i < l / 2; i++) counter[str[i].charCodeAt(0) - 'a'.charCodeAt(0)]++; for (let i = Math.floor(l / 2); i < l; i++) counter[str[i].charCodeAt(0) - 'a'.charCodeAt(0)]--; for (let i = 0; i < MAX; i++) if (counter[i] != 0) return true; return false; } // Driver function let str = "abcasdsabcae"; if (Function(str)) document.write("Yes, both halves" +" differ by at least one character"); else document.write("No, both halves" +" do not differ at all"); // This code is contributed by rag2127 </script> |
Output
Yes, both halves differ by at least one character
Time Complexity: O(N), as we are using a loop to traverse N times. Where N is the length of the string.
Auxiliary Space: O(26), as we are using extra space for counter array.
Method 3: (No extra space)
- Input the string in form of character array
- Sort the two strings separately
- Traverse the two halves together, if these differ at any point, return true
to the calling function
Implementation:
C++
// C++ implementation to check if // both halves of the string have // at least one different character #include <algorithm> #include <cstring> #include <iostream> #include <string> using namespace std; // Function which break string into two halves // Sorts the two halves separately // Compares the two halves // return true if any index has non-zero value bool function(char str[]) { int l = strlen(str); // Declaration and initialization // of counter array sort(str, str + (l / 2)); sort(str + (l / 2), str + l); for (int i = 0; i < l / 2; i++) if (str[i] != str[l / 2 + i]) return true; return false; } // Driver function int main() { char str[] = "abcasdsabcae"; if (function(str)) cout << "Yes, both halves differ by" <<" at least one character"; else cout << "No, both halves do" <<" not differ at all"; return 0; } |
Java
// Java implementation to check if // both halves of the string have // at least one different character import java.io.*; import java.util.*; class GFG { // Function which break string into two halves // Sorts the two halves separately // Compares the two halves // return true if any index has non-zero value static Boolean function(char str[]) { int l = str.length; // Declaration and initialization // of counter array Arrays.sort(str, 0, (l / 2)); Arrays.sort(str,(l / 2), l); for (int i = 0; i < l / 2; i++) if (str[i] != str[l / 2 + i]) return true; return false; } public static void main (String[] args) { char str[] = ("abcasdsabcae").toCharArray(); if (function(str)) System.out.println("Yes, both halves differ" + " by at least one character"); else System.out.println("No, both halves do" + " not differ at all"); } } // This code is contributed by Gitanjali. |
Python3
# Python implementation to check if # both halves of the string have # at least one different character # Function which break string into two halves # Sorts the two halves separately # Compares the two halves # return true if any index has non-zero value def function(st): st = list(st) l = len(st) # Declaration and initialization # of counter array st[:l//2] = sorted(st[:l//2]) st[l//2:] = sorted(st[l//2:]) for i in range(l//2): if (st[i] != st[l//2 + i]): return True return False # Driver function st = "abcasdsabcae"if function(st): print("Yes, both halves differ ", "by at least one character") else: print("No, both halves do not differ at all") # This code is contributed by Ansu Kumari |
C#
// C# implementation to check if // both halves of the string have // at least one different character using System; class GFG { // Function which break string into two halves // Sorts the two halves separately // Compares the two halves // return true if any index has non-zero value static Boolean function(char []str) { int l = str.Length; // Declaration and initialization // of counter array Array.Sort(str, 0, (l / 2)); Array.Sort(str,(l / 2), l-(l/2)); for (int i = 0; i < l / 2; i++) if (str[i] != str[l / 2 + i]) return true; return false; } // Driver code public static void Main (String[] args) { char []str = ("abcasdsabcae").ToCharArray(); if (function(str)) Console.WriteLine("Yes, both halves differ" + " by at least one character"); else Console.WriteLine("No, both halves do" + " not differ at all"); } } // This code contributed by Rajput-Ji |
Javascript
<script> // Javascript implementation to check if // both halves of the string have // at least one different character // Function which break string into two halves // Sorts the two halves separately // Compares the two halves // return true if any index has non-zero value function Function(str) { let l = str.length; // Declaration and initialization // of counter array str=(str.slice(0,Math.floor(l/2)).sort()).concat(str.slice(Math.floor(l/2),l).sort()); for (let i = 0; i < Math.floor(l / 2); i++) if (str[i] != str[(Math.floor(l / 2) + i)]) return true; return false; } let str="abcasdsabcae".split(""); if (Function(str)) document.write("Yes, both halves differ" + " by at least one character"); else document.write("No, both halves do" + " not differ at all"); // This code is contributed by avanitrachhadiya2155 </script> |
Output
Yes, both halves differ by at least one character
Time Complexity: O(N*logN), as we are using sorting
Auxiliary Space: O(1), as we are not using any extra space.
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