A less tricky solution would be to check if the frequency of the current character is greater than 1, and if it is, we slide our left pointer to the right until the frequency of the current char is not greater than 1.

function longestSubAllDistinctChar(str) { let freq = {}; let start = 0; let longest = 0;

for (let end = 0; end < str.length; end++) { const rChar = str[end]; if (!(rChar in freq)) { freq[rChar] = 0; } freq[rChar]++;

while (freq[rChar] > 1) { const lChar = str[start]; freq[lChar]--; start++; } longest = Math.max(longest, end - start + 1); }

return longest; }