204. Count Primes Count the number of prime numbers less than a non-negative number, n. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Example 1: Input: n = 10 Output: 4 Explanation: There are 4 prime numbers less than 10, they are 2, 3, 5, 7. Example 2: Input: n = 0 Output: 0 Example 3: Input: n = 1 Output: 0 Constraints: ...
11004. Max Consecutive Ones III Given a binary array nums and an integer k, return the maximum number of consecutive 1’s in the array if you can flip at most k 0’s. 1 2 3 4 5 6 7 8 9 10 11 12 13 Example 1: Input: nums = [1,1,1,0,0,0,1,1,1,1,0], k = 2 Output: 6 Explanation: [1,1,1,0,0,1,1,1,1,1,1] Bolded numbers were flipped from 0 to 1. The longest subarray is underlined. Example 2: Input: nums = [0,0,1,1,0,0,1,1,1,0,1,1,0,0,0,1,1,1,1], k = 3 Output: 10 Explanation: [0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,1,1,1,1] Bolded numbers were flipped from 0 to 1. The longest subarray is underlined. Constraints: ...
11. Container With Most Water Given n non-negative integers a1, a2, …, an , where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of the line i is at (i, ai) and (i, 0). Find two lines, which, together with the x-axis forms a container, such that the container contains the most water. Notice that you may not slant the container. ...
159. Longest Substring with At Most Two Distinct Characters Given a string s, return the length of the longest substring that contains at most two distinct characters. 1 2 3 4 5 6 7 8 9 10 11 Example 1: Input: s = "eceba" Output: 3 Explanation: The substring is "ece" which its length is 3. Example 2: Input: s = "ccaabbb" Output: 5 Explanation: The substring is "aabbb" which its length is 5. Constraints: ...
209. Minimum Size Subarray Sum Given an array of positive integers nums and a positive integer target, return the minimal length of a contiguous subarray [numsl, numsl+1, …, numsr-1, numsr] of which the sum is greater than or equal to target. If there is no such subarray, return 0 instead. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Example 1: Input: target = 7, nums = [2,3,1,2,4,3] Output: 2 Explanation: The subarray [4,3] has the minimal length under the problem constraint. Example 2: Input: target = 4, nums = [1,4,4] Output: 1 Example 3: Input: target = 11, nums = [1,1,1,1,1,1,1,1] Output: 0 Constraints: ...
3. Longest Substring Without Repeating Characters Given a string s, find the length of the longest substring without repeating characters. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Example 1: Input: s = "abcabcbb" Output: 3 Explanation: The answer is "abc", with the length of 3. Example 2: Input: s = "bbbbb" Output: 1 Explanation: The answer is "b", with the length of 1. Example 3: Input: s = "pwwkew" Output: 3 Explanation: The answer is "wke", with the length of 3. Notice that the answer must be a substring, "pwke" is a subsequence and not a substring. Example 4: Input: s = "" Output: 0 Constraints: ...
424. Longest Repeating Character Replacement You are given a string s and an integer k. You can choose any character of the string and change it to any other uppercase English character. You can perform this operation at most k times. Return the length of the longest substring containing the same letter you can get after performing the above operations. 1 2 3 4 5 6 7 8 9 10 11 12 Example 1: Input: s = "ABAB", k = 2 Output: 4 Explanation: Replace the two 'A's with two 'B's or vice versa. Example 2: Input: s = "AABABBA", k = 1 Output: 4 Explanation: Replace the one 'A' in the middle with 'B' and form "AABBBBA". The substring "BBBB" has the longest repeating letters, which is 4. Constraints: ...
340. Longest Substring with At Most K Distinct Characters Given a string s and an integer k, return the length of the longest substring of s that contains at most k distinct characters. 1 2 3 4 5 6 7 8 9 10 11 Example 1: Input: s = "eceba", k = 2 Output: 3 Explanation: The substring is "ece" with length 3. Example 2: Input: s = "aa", k = 1 Output: 2 Explanation: The substring is "aa" with length 2. Constraints: ...
76. Minimum Window Substring Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string “”. The testcases will be generated such that the answer is unique. A substring is a contiguous sequence of characters within the string. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Example 1: Input: s = "ADOBECODEBANC", t = "ABC" Output: "BANC" Explanation: The minimum window substring "BANC" includes 'A', 'B', and 'C' from string t. Example 2: Input: s = "a", t = "a" Output: "a" Explanation: The entire string s is the minimum window. Example 3: Input: s = "a", t = "aa" Output: "" Explanation: Both 'a's from t must be included in the window. Since the largest window of s only has one 'a', return empty string. Constraints: ...
1625. Lexicographically Smallest String After Applying Operations Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well. 1 2 3 4 Example 1: Input: head = [1,1,2] Output: [1,2] 1 2 3 4 Example 2: Input: head = [1,1,2,3,3] Output: [1,2,3] ...