398. Random Pick Index Total Accepted: 6047 Total Submissions: 16791 Difficulty: Medium Contributors: Admin Given an array of integers with possible duplicates, randomly output the index of a given target number. You can assume that the given target number must exist in the array. Note:The array size can be very large. Solution that uses too …
Monthly Archives: October 2016
Leetcode 49: Group Anagrams
49. Group Anagrams Total Accepted: 98283 Total Submissions: 321031 Difficulty: Medium Contributors: Admin Given an array of strings, group anagrams together. For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return: [ [“ate”, “eat”,”tea”], [“nat”,”tan”], [“bat”] ] Note: All inputs will be in lower-case. Code from collections import defaultdict class Solution(object): def groupAnagrams(self, strs): …
Leetcode 48: Rotate Image
48. Rotate Image Total Accepted: 84852 Total Submissions: 232792 Difficulty: Medium Contributors: Admin You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up:Could you do this in-place? General Idea: You need to first flip matrix upside down. Then swap elements mirror to …
Leetcode 13: Roman to Integer
13. Roman to Integer Total Accepted: 111025 Total Submissions: 261201 Difficulty: Easy Contributors: Admin Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. Code class Solution(object): def romanToInt(self, s): “”” :type s: str :rtype: int “”” pre = 0 sum = 0 …
Leetcode 17: Letter Combinations of a Phone Number
17. Letter Combinations of a Phone Number Total Accepted: 104864 Total Submissions: 335917 Difficulty: Medium Contributors: Admin Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string “23” Output: [“ad”, “ae”, “af”, “bd”, “be”, …
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Leetcode 16: 3Sum Closest
https://leetcode.com/problems/3sum-closest/ 16. 3Sum Closest Total Accepted: 97996 Total Submissions: 324135 Difficulty: Medium Contributors: Admin Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. …
Leetcode 12: Integer to Roman
12. Integer to Roman Total Accepted: 80645 Total Submissions: 192971 Difficulty: Medium Contributors: Admin Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. Code class Solution(object): def intToRoman(self, num): “”” :type num: int :rtype: str “”” M = [“”, “M”, “MM”, “MMM”] …
Leetcode 11: Container With Most Water
11. Container With Most Water Total Accepted: 99353 Total Submissions: 277586 Difficulty: Medium Contributors: Admin 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 line i is at (i, ai) and (i, 0). Find two lines, …
Leetcode 125: Valid Palindrome
125. Valid Palindrome Total Accepted: 124387 Total Submissions: 499823 Difficulty: Easy Contributors: Admin Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"A man, a plan, a canal: Panama" is a palindrome."race a car" is not a palindrome. Note:Have you consider that the string might be empty? …
Leetcode 131: Palindrome Partitioning
131. Palindrome Partitioning Total Accepted: 77657 Total Submissions: 260955 Difficulty: Medium Contributors: Admin Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s. For example, given s = "aab",Return [ [“aa”,”b”], [“a”,”a”,”b”] ] Code class Solution(object): def partition(self, s): “”” …