#1593 - Split a String Into the Max Number of Unique Substrings

Medium • View on LeetCode • View on GitHub

Problem Description

Given a string s, return the maximum number of unique substrings that the given string can be split into.

You can split string s into any list of non-empty substrings, where the concatenation of the substrings forms the original string. However, you must split the substrings such that all of them are unique.

A substring is a contiguous sequence of characters within a string.

Solution

/**
 * @param {string} s
 * @return {number}
 */
var maxUniqueSplit = function(s) {
  return backtrack(0, new Set());

  function backtrack(start, seen) {
    if (start === s.length) return seen.size;

    let maxSplits = 0;
    for (let end = start + 1; end <= s.length; end++) {
      const substring = s.slice(start, end);
      if (!seen.has(substring)) {
        seen.add(substring);
        maxSplits = Math.max(maxSplits, backtrack(end, seen));
        seen.delete(substring);
      }
    }

    return maxSplits;
  }
};