LeetCode — Two Pointers

Two Pointers of Tips:

• Double pointer sliding window classical writing method. The right pointer moves to the right until it can no longer move to the right (depending on the problem). When the right pointer reaches the far right, start moving the left pointer to release the window left boundary. Problem 3. 76, 209, 438, 567, 713, 763, 845, 881, 904, 992, 1004.

	left, right := 0.- 1

	for left < len(s) {
		if right+1 < len(s) && freq[s[right+1] -'a'] = =0 {
			freq[s[right+1] -'a']++
			right++
		} else {
			freq[s[left]-'a']--
			left++
		}
		result = max(result, right-left+1)}Copy the code

• Fast and slow Pointers can find repeated numbers. Time complexity O(n), problem 287.
• After substituting letters, the longest consecutive length of the same letter can appear. The 424th.
• SUM problem set. Problem 1, 15, 16, 18, 167, 923.