15 Jun 2024•C++ / Python / TypeScript•Easy

Isomorphic Strings

Collected C++, Python, TypeScript solutions for isomorphic strings. Add a dedicated write-up later if you want deeper notes.

View original LeetCode question

auto-generated entry for Isomorphic Strings. the solution files are available below.

solution files

C++ isomorphic-strings/synced-solution.cpp
Python isomorphic-strings/synced-solution.py
TypeScript isomorphic-strings/synced-solution.ts

Solution files

Python•isomorphic-strings/synced-solution.py

def isIsomorphic(s: str, t: str) -> bool:
    if len(s) != len(t):
        return False

    s_to_t = {}
    t_to_s = {}

    for char_s, char_t in zip(s, t):
        if char_s in s_to_t:
            if s_to_t[char_s] != char_t:
                return False
        else:
            s_to_t[char_s] = char_t

        if char_t in t_to_s:
            if t_to_s[char_t] != char_s:
                return False
        else:
            t_to_s[char_t] = char_s

    return True

C++•isomorphic-strings/synced-solution.cpp

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        if (s.length() != t.length()) return false;

        unordered_map<char, char> sToT;
        unordered_map<char, char> tToS;

        for (int i = class="syntax-number">0; i < s.length(); i++) {
            char charS = s[i];
            char charT = t[i];

            if (sToT.count(charS)) {
                if (sToT[charS] != charT) return false;
            } else {
                sToT[charS] = charT;
            }

            if (tToS.count(charT)) {
                if (tToS[charT] != charS) return false;
            } else {
                tToS[charT] = charS;
            }
        }

        return true;
    }
};

TypeScript•isomorphic-strings/synced-solution.ts

function isIsomorphic(s: string, t: string): boolean {
    if (s.length !== t.length) return false;

    const sToT = new Map<string, string>();
    const tToS = new Map<string, string>();

    for (let i = class="syntax-number">0; i < s.length; i++) {
        const charS = s[i];
        const charT = t[i];

        if (sToT.has(charS)) {
            if (sToT.get(charS) !== charT) return false;
        } else {
            sToT.set(charS, charT);
        }

        if (tToS.has(charT)) {
            if (tToS.get(charT) !== charS) return false;
        } else {
            tToS.set(charT, charS);
        }
    }

    return true;
}