# 57. Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that the intervals were initially sorted according to their start times. E...# 56. Merge Intervals

Given a collection of intervals, merge all overlapping intervals. For example, Given [1,3],[2,6],[8,10],[15,18], return [1,6],[8,10],[15,18]. 该题目用Greedy，先对start的时间进行从...# 174. Dungeon Game

The demons had captured the princess (**P**) and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of M x N rooms laid out in a 2D grid. Our valiant knight (

**K**) was...

# 64. Minimum Path 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.

**Note:**You can only ...

# 152. Maximum Product Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4], the contiguous subarray [2,3] has the largest ...# 322. Coin Change

You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money ...# Best Time to Buy and Sell Stock I,II,III

**Best Time to Buy and Sell Stock I**Say you have an array for which the

*i*th element is the price of a given stock on day

*i*. If you were only permitted to complete at...

# 279. Perfect Squares

Given a positive integer*n*, find the least number of perfect square numbers (for example,

`1, 4, 9, 16, ...`

) which sum to *n*. For example, given

*n*=

`12`

,...
# 84. Largest Rectangle in Histogram

Given*n*non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram. Above is a histogram where width ...