1191. K-Concatenation Maximum Sum
Given an integer array arr and an integer k, modify the array by repeating it k times.
For example, if arr = [1, 2] and k = 3 then the modified array will be [1, 2, 1, 2, 1, 2].
Return the maximum sub-array sum in the modified array. Note that the length of the sub-array can be 0 and its sum in that case is 0.
As the answer can be very large, return the answer modulo 10^9 + 7.
Find the smallest prime palindrome greater than or equal to N.
Recall that a number is prime if it’s only divisors are 1 and itself, and it is greater than 1.
For example, 2,3,5,7,11 and 13 are primes.
Recall that a number is a palindrome if it reads the same from left to right as it does from right to left.
For example, 12321 is a palindrome.
Given a string IP, return “IPv4” if IP is a valid IPv4 address, “IPv6” if IP is a valid IPv6 address or “Neither” if IP is not a correct IP of any type.
A valid IPv4 address is an IP in the form “x1.x2.x3.x4” where 0 <= xi <= 255 and xi cannot contain leading zeros. For example, “192.168.1.1” and “192.168.1.0” are valid IPv4 addresses but “192.168.01.1”, while “192.168.1.00” and “192.168@1.1” are invalid IPv4 addresses.
A valid IPv6 address is an IP in the form “x1:x2:x3:x4:x5:x6:x7:x8” where:
- 1 <= xi.length <= 4
- xi is a hexadecimal string which may contain digits, lower-case English letter (‘a’ to ‘f’) and upper-case English letters (‘A’ to ‘F’).
- Leading zeros are allowed in xi.
For example, “2001:0db8:85a3:0000:0000:8a2e:0370:7334” and “2001:db8:85a3:0:0:8A2E:0370:7334” are valid IPv6 addresses, while “2001:0db8:85a3::8A2E:037j:7334” and “02001:0db8:85a3:0000:0000:8a2e:0370:7334” are invalid IPv6 addresses.
Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to a multiple of k, that is, sums up to n*k where n is also an integer.
Your country has an infinite number of lakes. Initially, all the lakes are empty, but when it rains over the nth lake, the nth lake becomes full of water. If it rains over a lake which is full of water, there will be a flood. Your goal is to avoid the flood in any lake.
Given an integer array rains where:
- rains[i] > 0 means there will be rains over the rains[i] lake.
- rains[i] == 0 means there are no rains this day and you can choose one lake this day and dry it.
Return an array ans where:
- ans.length == rains.length
- ans[i] == -1 if rains[i] > 0.
- ans[i] is the lake you choose to dry in the ith day if rains[i] == 0.
If there are multiple valid answers return any of them. If it is impossible to avoid flood return an empty array.
Notice that if you chose to dry a full lake, it becomes empty, but if you chose to dry an empty lake, nothing changes. (see example 4)
Given an array nums of distinct positive integers, return the number of tuples (a, b, c, d) such that a b = c d where a, b, c, and d are elements of nums, and a != b != c != d.
1725. Number Of Rectangles That Can Form The Largest Square
You are given an array rectangles where rectangles[i] = [li, wi] represents the ith rectangle of length li and width wi.
You can cut the ith rectangle to form a square with a side length of k if both k <= li and k <= wi. For example, if you have a rectangle [4,6], you can cut it to get a square with a side length of at most 4.
Let maxLen be the side length of the largest square you can obtain from any of the given rectangles.
Return the number of rectangles that can make a square with a side length of maxLen.