输入一个正整数m(20<=m<=100)，计算 11+12+13+...+m 的值。 ​ 输入格式:

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

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique s...

Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn’t one, retur...

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).

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, …) which sum to n.

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximum product you c...