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السلاسل المميزة مع التغييرات الفردية والزوجية مسموح بها

بالنظر إلى مجموعة من السلاسل ذات الأحرف الصغيرة، تتمثل المهمة في العثور على عدد السلاسل المميزة. يتم التمييز بين سلسلتين إذا كان تطبيق العمليات التالية على سلسلة واحدة لا يمكن تشكيل السلسلة الثانية.  

  • يمكن تبديل الحرف الموجود في الفهرس الفردي بحرف آخر في الفهرس الفردي فقط.
  • يمكن تبديل الحرف الموجود في الفهرس الزوجي بحرف آخر في الفهرس الزوجي فقط.

أمثلة:   

Input : arr[] = {'abcd' 'cbad' 'bacd'} Output : 2 The 2nd string can be converted to the 1st by swapping the first and third characters. So there are 2 distinct 
strings as the third string cannot be converted to the first. Input : arr[] = {'abc' 'cba'} Output : 1 

أ حل بسيط هو تشغيل حلقتين. تختار الحلقة الخارجية سلسلة وتتحقق الحلقة الداخلية مما إذا كانت هناك سلسلة سابقة يمكن تحويلها إلى سلسلة حالية عن طريق إجراء التحويلات المسموح بها. يتطلب هذا الحل O(n2م) الوقت حيث n هو عدد السلاسل وm هو الحد الأقصى لعدد الأحرف في أي سلسلة.



ان حل فعال ينشئ سلسلة مشفرة لكل سلسلة إدخال. يحتوي المشفر على عدد من الأحرف الزوجية والفردية مفصولة بفاصل. تعتبر سلسلتان متماثلتين إذا كانت سلاسلهما المشفرة متماثلة وإلا فلا. بمجرد أن يكون لدينا طريقة لتشفير السلاسل، فإن المشكلة تتلخص في حساب السلاسل المشفرة المميزة. هذه مشكلة نموذجية للتجزئة. نقوم بإنشاء مجموعة تجزئة وتخزين ترميزات السلاسل واحدًا تلو الآخر. إذا كان الترميز موجودًا بالفعل، فإننا نتجاهل السلسلة. وإلا فإننا نقوم بتخزين الترميز في عدد التجزئة والزيادة للسلاسل المميزة. 

تطبيق:

C++
#include   using namespace std; int MAX_CHAR = 26; string encodeString(char str[] int m) {  // hashEven stores the count of even indexed character  // for each string hashOdd stores the count of odd  // indexed characters for each string  int hashEven[MAX_CHAR];  int hashOdd[MAX_CHAR];  memset(hashEven0sizeof(hashEven));  memset(hashOdd0sizeof(hashOdd));  // creating hash for each string  for (int i = 0; i < m; i++) {  char c = str[i];  if ((i & 1) != 0) // If index of current character is odd  hashOdd[c-'a']++;  else  hashEven[c-'a']++;  }  // For every character from 'a' to 'z' we store its  // count at even position followed by a separator  // followed by count at odd position.  string encoding = '';  for (int i = 0; i < MAX_CHAR; i++) {  encoding += (hashEven[i]);  encoding += ('-');  encoding += (hashOdd[i]);  encoding += ('-');  }  return encoding; } // This function basically uses a hashing based set to // store strings which are distinct according // to criteria given in question. int countDistinct(string input[] int n) {  int countDist = 0; // Initialize result  // Create an empty set and store all distinct  // strings in it.  set<string> s;  for (int i = 0; i < n; i++) {  // If this encoding appears first time increment  // count of distinct encodings.  char char_array[input[i].length()];  strcpy(char_array input[i].c_str());  if (s.find(encodeString(char_array input[i].length())) == s.end()) {  s.insert(encodeString(char_arrayinput[i].length()));  countDist++;  }  }  return countDist; } int main() {  string input[] = {'abcd' 'acbd' 'adcb' 'cdba'  'bcda' 'badc'};  int n = sizeof(input)/sizeof(input[0]);  cout << countDistinct(input n) << 'n'; } // This code is contributed by Harshit Sharma. 
Java
// Java program to count distinct strings with // even odd swapping allowed. import java.util.HashSet; import java.util.Set; class GFG { static int MAX_CHAR = 26;  static String encodeString(char[] str) {  // hashEven stores the count of even indexed character  // for each string hashOdd stores the count of odd  // indexed characters for each string  int hashEven[] = new int[MAX_CHAR];  int hashOdd[] = new int[MAX_CHAR];  // creating hash for each string  for (int i = 0; i < str.length; i++) {  char c = str[i];  if ((i & 1) != 0) // If index of current character is odd  hashOdd[c-'a']++;  else  hashEven[c-'a']++;  }  // For every character from 'a' to 'z' we store its  // count at even position followed by a separator  // followed by count at odd position.  String encoding = '';  for (int i = 0; i < MAX_CHAR; i++) {  encoding += (hashEven[i]);  encoding += ('-');  encoding += (hashOdd[i]);  encoding += ('-');  }  return encoding;  }  // This function basically uses a hashing based set to // store strings which are distinct according // to criteria given in question.  static int countDistinct(String input[] int n) {  int countDist = 0; // Initialize result  // Create an empty set and store all distinct  // strings in it.  Set<String> s = new HashSet<>();  for (int i = 0; i < n; i++) {  // If this encoding appears first time increment  // count of distinct encodings.  if (!s.contains(encodeString(input[i].toCharArray()))) {  s.add(encodeString(input[i].toCharArray()));  countDist++;  }  }  return countDist;  }  public static void main(String[] args) {  String input[] = {'abcd' 'acbd' 'adcb' 'cdba'  'bcda' 'badc'};  int n = input.length;  System.out.println(countDistinct(input n));  } } 
Python3
# Python3 program to count distinct strings with # even odd swapping allowed. MAX_CHAR = 26 # Returns encoding of string that can be used  # for hashing. The idea is to return same encoding  # for strings which can become same after swapping  # a even positioned character with other even characters  # OR swapping an odd character with other odd characters. def encodeString(string): # hashEven stores the count of even indexed character # for each string hashOdd stores the count of odd # indexed characters for each string hashEven = [0] * MAX_CHAR hashOdd = [0] * MAX_CHAR # creating hash for each string for i in range(len(string)): c = string[i] if i & 1: # If index of current character is odd hashOdd[ord(c) - ord('a')] += 1 else: hashEven[ord(c) - ord('a')] += 1 # For every character from 'a' to 'z' we store its # count at even position followed by a separator # followed by count at odd position. encoding = '' for i in range(MAX_CHAR): encoding += str(hashEven[i]) encoding += str('-') encoding += str(hashOdd[i]) encoding += str('-') return encoding # This function basically uses a hashing based set to # store strings which are distinct according # to criteria given in question. def countDistinct(input n): countDist = 0 # Initialize result # Create an empty set and store all distinct # strings in it. s = set() for i in range(n): # If this encoding appears first time increment # count of distinct encodings. if encodeString(input[i]) not in s: s.add(encodeString(input[i])) countDist += 1 return countDist # Driver Code if __name__ == '__main__': input = ['abcd' 'acbd' 'adcb' 'cdba' 'bcda' 'badc'] n = len(input) print(countDistinct(input n)) # This code is contributed by # sanjeev2552 
C#
// C# program to count distinct strings with // even odd swapping allowed. using System; using System.Collections.Generic;    class GFG {  static int MAX_CHAR = 26;  static String encodeString(char[] str)   {  // hashEven stores the count of even   // indexed character for each string   // hashOdd stores the count of odd  // indexed characters for each string  int []hashEven = new int[MAX_CHAR];  int []hashOdd = new int[MAX_CHAR];  // creating hash for each string  for (int i = 0; i < str.Length; i++)   {  char m = str[i];    // If index of current character is odd  if ((i & 1) != 0)   hashOdd[m - 'a']++;  else  hashEven[m - 'a']++;  }  // For every character from 'a' to 'z'   // we store its count at even position   // followed by a separator   // followed by count at odd position.  String encoding = '';  for (int i = 0; i < MAX_CHAR; i++)   {  encoding += (hashEven[i]);  encoding += ('-');  encoding += (hashOdd[i]);  encoding += ('-');  }  return encoding;  }  // This function basically uses a hashing based set  // to store strings which are distinct according   // to criteria given in question.  static int countDistinct(String []input int n)   {  int countDist = 0; // Initialize result  // Create an empty set and store all distinct  // strings in it.  HashSet<String> s = new HashSet<String>();  for (int i = 0; i < n; i++)   {  // If this encoding appears first time  // increment count of distinct encodings.  if (!s.Contains(encodeString(input[i].ToCharArray())))   {  s.Add(encodeString(input[i].ToCharArray()));  countDist++;  }  }  return countDist;  }  // Driver Code  public static void Main(String[] args)   {  String []input = {'abcd' 'acbd' 'adcb'   'cdba' 'bcda' 'badc'};  int n = input.Length;  Console.WriteLine(countDistinct(input n));  } } // This code is contributed by 29AjayKumar 
JavaScript
<script>  // Javascript program to count distinct strings with  // even odd swapping allowed  let MAX_CHAR = 26;    function encodeString(str) {  // hashEven stores the count of even indexed character  // for each string hashOdd stores the count of odd  // indexed characters for each string  let hashEven = Array(MAX_CHAR).fill(0);  let hashOdd = Array(MAX_CHAR).fill(0);    // creating hash for each string  for (let i = 0; i < str.length; i++) {  let c = str[i];  if ((i & 1) != 0) // If index of current character is odd  hashOdd[c.charCodeAt() - 'a'.charCodeAt()]++;  else  hashEven[c.charCodeAt() - 'a'.charCodeAt()]++;    }      // For every character from 'a' to 'z' we store its  // count at even position followed by a separator  // followed by count at odd position.  let encoding = '';  for (let i = 0; i < MAX_CHAR; i++) {  encoding += (hashEven[i]);  encoding += ('-');  encoding += (hashOdd[i]);  encoding += ('-');  }  return encoding;  }    // This function basically uses a hashing based set to  // store strings which are distinct according  // to criteria given in question.  function countDistinct(input n) {  let countDist = 0; // Initialize result    // Create an empty set and store all distinct  // strings in it.  let s = new Set();  for (let i = 0; i < n; i++) {  // If this encoding appears first time increment  // count of distinct encodings.  if (!s.has(encodeString(input[i].split('')))) {  s.add(encodeString(input[i].split('')));  countDist++;  }  }    return countDist;  } // Driver program   let input = ['abcd' 'acbd' 'adcb' 'cdba'  'bcda' 'badc'];  let n = input.length;    document.write(countDistinct(input n)); </script> 

الإخراج
4

تعقيد الوقت : على) 
المساحة المساعدة : O(1)

 

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