LeetCode: Isomorphic Strings Solution

Approach

Use two hash tables

• one for mapping char to char
• one for avoiding the case of 2 char both mapping to 1 char

Implementation

1var isIsomorphic = function (s, t) {
2  const map = new Map()
3  const replaced = new Set()
4  const n = s.length
5
6  for (let i = 0; i < n; i++) {
7    if (map.has(s[i]) === false && replaced.has(t[i]) === false) {
8      map.set(s[i], t[i])
9      replaced.add(t[i])
10      continue
11    }
12
13    if (map.get(s[i]) !== t[i]) {
14      return false
15    }
16  }
17
18  return true
19}