Given an integer array nums, return the number of range sums that lie in [lower, upper] inclusive.Range sum S(i, j) is defined as the sum of the elements in nu...

Given a sorted positive integer array nums and an integer n, add/patch elements to the array such that any number in range [1, n] inclusive can be formed by the...

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.

Find the sum of all left leaves in a given binary tree.

Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target.

Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

Given a binary tree and a sum, find all root-to-leaf paths where each path’s sum equals the given sum.

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.