272. Closest Binary Search Tree Value II

2018-09-18

Problem description:

Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target.

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270. Closest Binary Search Tree Value

2018-09-17

Problem description:

Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.

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304. Range Sum Query 2D - Immutable

2018-09-05

Problem description:

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).

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160. Intersection of Two Linked Lists

2018-09-03

Problem description:

Write a program to find the node at which the intersection of two singly linked lists begins.

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403. Frog Jump

2018-09-03

Problem description:

A frog is crossing a river. The river is divided into x units and at each unit there may or may not exist a stone. The frog can jump on a stone, but it must not jump into the water.

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Flatten a multilevel linked list

2018-09-03

Problem description:

Given a linked list where in addition to the next pointer, each node has a child pointer, which may or may not point to a separate list. These child lists may have one or more children of their own, and so on, to produce a multilevel data structure, as shown in below figure.You are given the head of the first level of the list.

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157. Read N Characters Given Read4

2018-09-03

Problem description:

The API: int read4(char *buf) reads 4 characters at a time from a file.

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129. Sum Root to Leaf Numbers

2018-09-02

Problem description:

Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.

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30. Substring with Concatenation of All Words

2018-09-01

Problem description:

You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in words exactly once and without any intervening characters.

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23. Merge k Sorted Lists

2018-09-01

Problem description:

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.

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