Problem You are given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi. You can attend an event i at any day d where startTimei <= d <= endTimei. You can only attend one event at any time d. Return the maximum number of events you can attend. Examples Example 1: ...
Problem Given an array nums and a target value k, find the maximum length of a subarray that sums to k. If there isn’t one, return 0 instead. Note: The sum of the entire nums array is guaranteed to fit within the 32-bit signed integer range. Examples Example 1: Input: nums = [1, -1, 5, -2, 3], k = 3 Output: 4 Explanation: The subarray [1, -1, 5, -2] sums to 3 and is the longest. ...
Problem You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it. Examples 1 -> 10 -> 20 4 -> 11 -> 13 3 -> 8 -> 9 will result in 1 -> 3 -> 4 -> 8 -> 9 -> 10 -> 11 -> 13 -> 20 ...
Problem Given a string s. In one step you can insert any character at any index of the string. Return the minimum number of steps to make s palindrome. A Palindrome String is one that reads the same backward as well as forward. Examples Example 1: Input: s = "zzazz" Output: 0 Explanation: The string "zzazz" is already palindrome we don't need any insertions. ...
Problem You are playing the following Nim Game with your friend: Initially, there is a heap of stones on the table. You and your friend will alternate taking turns, and you go first. On each turn, the person whose turn it is will remove 1 to 3 stones from the heap. The one who removes the last stone is the winner. Given n, the number of stones in the heap, return true if you can win the game assuming both you and your friend play optimally, otherwise return false. ...
Problem Given the head of a singly linked list, group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list. The first node is considered odd, and the second node is even, and so on. Note that the relative order inside both the even and odd groups should remain as it was in the input. You must solve the problem in O(1) extra space complexity and O(n) time complexity. ...
Problem There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color. The cost of painting each house with a certain color is represented by a n x k cost matrix. For example, costs[0][0] is the cost of painting house 0 with color 0; costs[1][2] is the cost of painting house 1 with color 2, and so on… Find the minimum cost to paint all houses. ...
Problem Given the head of a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. You should preserve the original relative order of the nodes in each of the two partitions. Examples Example 1: --- title: Input --- graph LR A1[1]:::less --> B4[4]:::greater --> C3[3]:::pivot --> D2[2]:::less --> E5[5]:::greater --> F2[2]:::less classDef pivot fill:#ffb6c1,stroke:#000,stroke-width:2px; classDef less fill:#ffcc00,stroke:#000,stroke-width:2px; classDef greater fill:#add8e6,stroke:#000,stroke-width:2px; ...
Problem Given an integer array nums and an integer k, return true if it is possible to divide this array into k non-empty subsets whose sums are all equal. Examples Example 1: Input: nums = [4,3,2,3,5,2,1], k = 4 Output: true Explanation: It is possible to divide it into 4 subsets (5), (1, 4), (2,3), (2,3) with equal sums. ...
Problem Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal’s triangle. In Pascal’s triangle, each number is the sum of the two numbers directly above it as shown: ...