8987. Character replacement

Replace all occurrences of the letter ‘a’ with ‘b’ and vice versa in the given string.

Input. One string with a length of no more than 200 characters, containing only Latin letters and spaces.

Output. Print the string with the replacements made.

Sample input	Sample output
abrakadabra	barbkbdbarb

SOLUTION

strings

Algorithm analysis

Read the input string and replace all occurrences of ‘a’ with ‘b’ and vice versa.

Algorithm implementation

Declare a character array to store the string.

char s[200];

Read the input string.

gets(s);

Iterate over the characters of the string. Each letter ‘a’ is replaced with ‘b’. Each letter ‘b’ is replaced with ‘a’.

for (i = 0; i < strlen(s); i++)

if (s[i] == 'a') s[i] = 'b';

else if (s[i] == 'b') s[i] = 'a';

Print the updated string.

puts(s);

Algorithm implementation – С++

Read the input string.

getline(cin, s);

Iterate over the characters of the string. Each letter ‘a’ is replaced with ‘b’. Each letter ‘b’ is replaced with ‘a’.

for (i = 0; i < s.size(); i++)

if (s[i] == 'a') s[i] = 'b';

else if (s[i] == 'b') s[i] = 'a';

Print the updated string.

cout << s << endl;

Java implementation

import java.util.*;

public class Main

{

public static void main(String[] args)

{

Scanner con = new Scanner(System.in);

String s = con.nextLine();

s = s.replace('a', '0');

s = s.replace('b', 'a');

s = s.replace('0', 'b');

System.out.println(s);

con.close();

}

}

Python implementation

Read the input string.

s = input()

Temporarily replace all occurrences of the letter ‘a’ with the character ‘0’, which does not appear in the string. The replace method does not modify the original string but returns a new string with the replacements. This is because strings in Python are immutable.

s = s.replace('a','0')

Replace all occurrences of the letter ‘b’ with the letter ‘a’.

s = s.replace('b','a')

Replace all occurrences of the letter ‘0’ with the letter ‘b’.

s = s.replace('0','b')

Print the updated string.

print(s)