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LeetCode84

LeetCode.H-Index II Problem: Given an array of citations sorted in ascending order (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index. According to the definition of h-index on Wikipedia: "A scientist has index h if h of his/her N papers have at least h citations each, and the other N − h papers have no more than h citations each." Example: Input: citatio.. 2020. 6. 19.
LeetCode. Missing Number [Bit] Problem: Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. Example 1: Input: [3,0,1] Output: 2 Example 2: Input: [9,6,4,2,3,5,7,0,1] Output: 8 Note: Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity? -Summary- 1. Bit operation on length of the nums list and .. 2020. 6. 19.
LeetCode 41. First Missing Positive Problem: Given an unsorted integer array, find the smallest missing positive integer. Example 1: Input: [1,2,0] Output: 3 Example 2: Input: [3,4,-1,1] Output: 2 Example 3: Input: [7,8,9,11,12] Output: 1 -Summary- 1. Set first positive integer as 1 --> posNum 2. loop-through the nums and check if posNum is in the nums list. (max int: 2^31 -1) - if there is, adding 1 more value to posNum and find .. 2020. 6. 18.
LeetCode.Surrounded Regions Problem: Given a 2D board containing 'X' and 'O' (the letter O), capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. Example: Explanation: Surrounded regions shouldn’t be on the border, which means that any 'O' on the border of the board are not flipped to 'X'. Any 'O' that is not on the border and it is not connected to an 'O' on.. 2020. 6. 18.
LeetCode 665. Non-decreasing Array Problem: Given an array nums with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element. We define an array is non-decreasing if nums[i] 2020. 6. 18.
LeetCode.Hamming Distance [Bit] Problem: The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Given two integers x and y, calculate the Hamming distance. Note: 0 ≤ x, y < 231. Example: Input: x = 1, y = 4 Output: 2 Explanation: 1 (0 0 0 1) 4 (0 1 0 0) ↑ ↑ The above arrows point to positions where the corresponding bits are different. -Summary- Used bin() method and.. 2020. 6. 18.