# How to check whether the given strings are isomorphic using C#?

CsharpServer Side ProgrammingProgramming

Two strings, X and Y, are called isomorphic if all occurrences of each character in X can be replaced with another character to get Y and vice-versa. For example, consider strings ACAB and XCXY. All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character, but a character may map to itself.

## Example 1

Input − s = "egg", t = "add"

Output − true

## Example 2

Input − s = "foo", t = "bar"

Output − false

Time complexity − O(N)

Space complexity − O(N)

## code

public class Arrays{
public bool IsStringIsomorphic(string s, string t){
if (s == null || t == null){
return false;
}
int[] chars1 = new int[128];
int[] chars2 = new int[128];
for (int i = 0; i < s.Length; i++){
if (chars1[s[i]] != chars2[t[i]]){
return false;
}
else{
chars1[s[i]] = i + 1;
chars2[t[i]] = i + 1;
}
}
return true;
}
}

static void Main(string[] args){
}
True