leetcode Find K Pairs with Smallest Sums
You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.
Define a pair (u,v) which consists of one element from the first array and one element from the second array.
Find the k pairs (u1,v1),(u2,v2) …(uk,vk) with the smallest sums.
123456 Given nums1 = [1,7,11], nums2 = [2,4,6], k = 3Return: [1,2],[1,4],[1,6]The first 3 pairs are returned from the sequence:[1,2],[1,4],[1,6],[7,2],[7,4],[11,2],[7,6],[11,4],[11,6]
123456 Given nums1 = [1,1,2], nums2 = [1,2,3], k = 2Return: [1,1],[1,1]The first 2 pairs are returned from the sequence:[1,1],[1,1],[1,2],[2,1],[1,2],[2,2],[1,3],[1,3],[2,3]
123456 Given nums1 = [1,2], nums2 = , k = 3Return: [1,3],[2,3]All possible pairs are returned from the sequence:[1,3],[2,3]
leetcode Super Pow
Your task is to calculate ab mod 1337 where a is a positive integer and b is an extremely large positive integer given in the form of an array.
1234 a = 2b = Result: 8
1234 a = 2b = [1,0]Result: 1024
leetcode Sum of Two Integers
Calculate the sum of two integers a and b, but you are not allowed to use the operator
Given a = 1 and b = 2, return 3.
leetcode Largest Divisible Subset
Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies: Si % Sj = 0 or Sj% Si = 0.
If there are multiple solutions, return any subset is fine.
123 nums: [1,2,3]Result: [1,2] (of course, [1,3] will also be ok)
123 nums: [1,2,4,8]Result: [1,2,4,8]
leetcode Valid Perfect Square
Given a positive integer num, write a function which returns True if num is a perfect square else False.
Note: Do not use any built-in library function such as
12 Input: 16Returns: True
12 Input: 14Returns: False
leetcode Water and Jug Problem
You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactly z litres using these two jugs.
- Fill any of the jugs completely.
- Empty any of the jugs.
- Pour water from one jug into another till the other jug is completely full or the first jug itself is empty.
12 Input: x = 2, y = 6, z = 4Output: True
12 Input: x = 2, y = 6, z = 5Output: False
leetcode Max Sum of Rectangle No Larger Than K
Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is no larger than k.
12345 Given matrix = [[1, 0, 1],[0, -2, 3]]k = 2
The answer is
2. Because the sum of rectangle
[[0, 1], [-2, 3]]is 2 and 2 is the max number no larger than k (k = 2).
- The rectangle inside the matrix must have an area > 0.
- What if the number of rows is much larger than the number of columns?
leetcode Count Numbers with Unique Digits
Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n.
Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x < 100, excluding
leetcode Top K Frequent Elements
Given a non-empty array of integers, return the k most frequent elements.
[1,1,1,2,2,3]and k = 2, return
- You may assume k is always valid, 1 ≤ k ≤ number of unique elements.
- Your algorithm’s time complexity must be better than O(n log n), where n is the array’s size.
leetcode Reverse String
Write a function that takes a string as input and returns the string reversed.
Given s = “hello”, return “olleh”.