DSA Interview Challenges

Making File Names Unique

Save all the file names in a map with their frequency & if a file name is already present, append a number to it
Continue until a unique file name is found and update the map with the new file name as well and its frequency


/**
 * @param {string[]} names
 * @return {string[]}
 */
var getFolderNames = function (names) {
  const freq = new Map();
 
  for (let i = 0; i < names.length; i++) {
    let key = names[i];
    let count = freq.get(key) ?? 0;
 
    while (freq.has(key)) {
      key = names[i] + `(${++count})`;
    }
 
    freq.set(key, 0);
    freq.set(names[i], count);
    names[i] = key;
  }
 
  return names;
};

Complexity

Time: O(n)
Space: O(n)