Isomorphic Strings

main.js

// Given two strings s and t, determine if they are isomorphic.
// Two strings are isomorphic if there is a one-to-one mapping
// possible for every character of the first string to every
// character of the second string. 

function isIsomorphic(a, b) {
  if (a.length !== b.length) return false;

  let mapping = {};
  for (let i = 0; i < a.length; i++) {
    if (mapping[a[i]] === undefined) {
      mapping[a[i]] = b[i];
      continue;
    }

    if (mapping[a[i]] !== b[i]) return false;
  }
  return true;
}

if (import.meta.main) {
  console.log(isIsomorphic("abb", "bcc"));
  console.log(isIsomorphic("william", "foobaar"));
  console.log(isIsomorphic("foobar", "baz"));
  console.log(isIsomorphic("will", "1233"));
}