750. Number Of Corner Rectangles
Given an m x n integer matrix grid where each entry is only 0 or 1, return the number of corner rectangles.
A corner rectangle is four distinct 1’s on the grid that forms an axis-aligned rectangle. Note that only the corners need to have the value 1. Also, all four 1’s used must be distinct.
In a town, there are n people labeled from 1 to n. There is a rumor that one of these people is secretly the town judge.
If the town judge exists, then:
- The town judge trusts nobody.
- Everybody (except for the town judge) trusts the town judge.
- There is exactly one person that satisfies properties 1 and 2.
You are given an array trust where trust[i] = [ai, bi] representing that the person labeled ai trusts the person labeled bi.
Return the label of the town judge if the town judge exists and can be identified, or return -1 otherwise.
1150. Check If a Number Is Majority Element in a Sorted Array
Given an integer array nums sorted in non-decreasing order and an integer target, return true if target is a majority element, or false otherwise.
A majority element in an array nums is an element that appears more than nums.length / 2 times in the array.
Given a string s, return true if the s can be palindrome after deleting at most one character from it.
Given an integer array nums, return the maximum difference between two successive elements in its sorted form. If the array contains less than two elements, return 0.
You must write an algorithm that runs in linear time and uses linear extra space.
The set [1, 2, 3, …, n] contains a total of n! unique permutations.
By listing and labeling all of the permutations in order, we get the following sequence for n = 3:
- “123”
- “132”
- “213”
- “231”
- “312”
- “321”
Given n and k, return the kth permutation sequence.