Character replacement after removing duplicates from a string
Given a string. The task is to replace each character of the minimized string with a character present at the index ‘IND‘ of the original string. The minimized string is the string obtained by removing all duplicates from the original string keeping the order of elements the same.
IND for any index in the minimized string is calculated as:
IND = (square of ascii value of minimized string character) % (length of original string)
Examples:
Input : Beginner Output : sesg Explanation : minimized string = geks length of original string = 5 ascii value of g = 103 IND for g = (103*103) % 5 = 4 replacement character for g = s character 's' present at index 4 of original string Similarly, replacement character for e = e replacement character for k = s replacement character for s = g Input : helloworld Output : oeoeeoh
Approach:
Below is the step-by-step algorithm for string minimization:
1. Initialize flagchar[26] = {0} 2. for i=0 to str.length()-1 3. ch = str[i] 4. if flagchar[ch-97] == 0 then 5. mstr = mstr + ch 6. flagchar[ch-97] = 1 7. End if 8. End of loop 9. return mstr // minimized string
Algorithm for character replacement:
1. Replace each character of minimized string as described in the problem statement and example 2. Compute final string
Below is the implementation of the above approach:
C++
// C++ program for character replacement // after string minimization #include <bits/stdc++.h> using namespace std; // Function to minimize string string minimize(string str) { string mstr = " " ; int l, i, flagchar[26] = { 0 }; char ch; l = str.length(); // duplicate characters are removed for (i = 0; i < str.length(); i++) { ch = str.at(i); // checks if character has previously occurred or not // if not then add it to the minimized string 'mstr' if (flagchar[ch - 97] == 0) { mstr = mstr + ch; flagchar[ch - 97] = 1; } } return mstr; // minimized string } // Utility function to print the // minimized, replaced string void replaceMinimizeUtil(string str) { string minimizedStr, finalStr = "" ; int i, index, l; char ch; l = str.length(); minimizedStr = minimize(str); // minimized string // Creating final string by replacing character for (i = 0; i < minimizedStr.length(); i++) { ch = minimizedStr.at(i); // index calculation index = (ch * ch) % l; finalStr = finalStr + str.at(index); } cout << "Final string: " << finalStr; // final string } // Driver program int main() { string str = "Beginner" ; replaceMinimizeUtil(str); return 0; } |
Java
// Java program for character replacement // after String minimization class GFG { // Function to minimize String static String minimize(String str) { String mstr = " " ; int l, i, flagchar[] = new int [ 26 ]; char ch; l = str.length(); // duplicate characters are removed for (i = 0 ; i < str.length(); i++) { ch = str.charAt(i); // checks if character has previously occurred or not // if not then add it to the minimized String 'mstr' if (flagchar[ch - 97 ] == 0 ) { mstr = mstr + ch; flagchar[ch - 97 ] = 1 ; } } return mstr; // minimized String } // Utility function to print the // minimized, replaced String static void replaceMinimizeUtil(String str) { String minimizedStr, finalStr = "" ; int i, index, l; char ch; l = str.length(); minimizedStr = minimize(str); // minimized String // Creating final String by replacing character for (i = 0 ; i < minimizedStr.length(); i++) { ch = minimizedStr.charAt(i); // index calculation index = (ch * ch) % l; finalStr = finalStr + str.charAt(index); } // final String System.out.println( "Final String: " + finalStr); } // Driver program public static void main(String[] args) { String str = "Beginner" ; replaceMinimizeUtil(str); } } // This code is contributed by Rajput-JI |
Python3
# Python3 program for character # replacement after string minimization # Function to minimize string def minimize(string): mstr = " " flagchar = [ 0 ] * 26 l = len (string) # Duplicate characters are removed for i in range ( 0 , len (string)): ch = string[i] # checks if character has previously occurred or not # if not then add it to the minimized string 'mstr' if flagchar[ ord (ch) - 97 ] = = 0 : mstr = mstr + ch flagchar[ ord (ch) - 97 ] = 1 return mstr # minimized string # Utility function to print the # minimized, replaced string def replaceMinimizeUtil(string): finalStr = "" l = len (string) minimizedStr = minimize(string) # minimized string # Creating final string by replacing character for i in range ( 0 , len (minimizedStr)): ch = ord (minimizedStr[i]) # index calculation index = (ch * ch) % l finalStr = finalStr + string[index] print ( "Final string:" , finalStr) # final string # Driver program if __name__ = = "__main__" : string = "Beginner" replaceMinimizeUtil(string) # This code is contributed by Rituraj Jain |
C#
// C# program for character replacement // after String minimization using System; class GFG { // Function to minimize String static String minimize( string str) { string mstr = " " ; int l, i; int [] flagchar = new int [26]; char ch; l = str.Length; // duplicate characters are removed for (i = 0; i < str.Length; i++) { ch = str[i]; // checks if character has previously // occurred or not if not then add it // to the minimized String 'mstr' if (flagchar[ch - 97] == 0) { mstr = mstr + ch; flagchar[ch - 97] = 1; } } return mstr; // minimized String } // Utility function to print the // minimized, replaced String static void replaceMinimizeUtil( string str) { string minimizedStr, finalStr = "" ; int i, index, l; char ch; l = str.Length; minimizedStr = minimize(str); // minimized String // Creating final String by // replacing character for (i = 0; i < minimizedStr.Length; i++) { ch = minimizedStr[i]; // index calculation index = (ch * ch) % l; finalStr = finalStr + str[index]; } // final String Console.Write( "Final String: " + finalStr); } // Driver Code public static void Main() { string str = "Beginner" ; replaceMinimizeUtil(str); } } // This code is contributed // by ChitraNayal |
PHP
<?php // PHP program for character replacement // after string minimization // Function to minimize string function minimize( $str ) { $mstr = " " ; $flagchar = array_fill (0, 26, 0); $l = strlen ( $str ); // duplicate characters are removed for ( $i = 0; $i < strlen ( $str ); $i ++) { $ch = $str [ $i ]; // checks if character has previously occurred or not // if not then add it to the minimized string 'mstr' if ( $flagchar [ord( $ch ) - 97] == 0) { $mstr .= $ch ; $flagchar [ord( $ch ) - 97] = 1; } } return $mstr ; // minimized string } // Utility function to print the // minimized, replaced string function replaceMinimizeUtil( $str ) { $finalStr = "" ; $l = strlen ( $str ); $minimizedStr = minimize( $str ); // minimized string // Creating final string by replacing character for ( $i = 0; $i < strlen ( $minimizedStr ); $i ++) { $ch = $minimizedStr [ $i ]; // index calculation $index = (ord( $ch ) * ord( $ch )) % $l ; $finalStr = $finalStr . $str [ $index ]; } echo "Final string: " . $finalStr ; // final string } // Driver code $str = "Beginner" ; replaceMinimizeUtil( $str ); // This code is contributed by mits ?> |
Javascript
<script> // Javascript program for character replacement // after String minimization // Function to minimize String function minimize(str) { let mstr = " " ; let l, i, flagchar = new Array(26); for (let i = 0; i < 26; i++) { flagchar[i] = 0; } let ch; l = str.length; // Duplicate characters are removed for (i = 0; i < str.length; i++) { ch = str[i]; // Checks if character has previously // occurred or not if not then add it // to the minimized String 'mstr' if (flagchar[ch.charCodeAt(0) - 97] == 0) { mstr = mstr + ch; flagchar[ch.charCodeAt(0) - 97] = 1; } } // Minimized String return mstr; } // Utility function to print the // minimized, replaced String function replaceMinimizeUtil(str) { let minimizedStr, finalStr = "" ; let i, index, l; let ch; l = str.length; // Minimized String minimizedStr = minimize(str); // Creating final String by replacing character for (i = 0; i < minimizedStr.length; i++) { ch = minimizedStr[i].charCodeAt(0); // Index calculation index = (ch * ch) % l; finalStr = finalStr + str[index]; } // Final String document.write( "Final String: " + finalStr); } // Driver code let str = "Beginner" ; replaceMinimizeUtil(str); // This code is contributed by avanitrachhadiya2155 </script> |
Output
Final string: ssesg
Time Complexity: O(n), where n is the length of the given string.
Auxiliary Space: O(n)
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