IT Crowd的博客

118. Pascal's Triangle题目描述解题思路实现代码 题目描述 Given a non-negative integer numRows, generate the first numRows of Pascal’s triangle. 杨辉三角形：第i行第j个元素值=第i-1行第j-1个元素值+第j个元素值 In Pascal’s triangle, each number i...

88. Merge Sorted Array合并两个有序数组题目描述思路实现 题目描述 Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note: The number of elements initialized in nums1 and nums2 are...

28. Implement strStr(）题目描述思路实现 题目描述 Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Input: haystack = “hello”, needle = “ll” Output:...

73. Set Matrix Zeroes矩阵置0题目描述思路实现 题目描述 Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in-place. Example 1: Input: [ [1,1,1], [1,0,1], [1,1,1] ] Output: [ [1,0,1], ...

2. Add Two Numbers两数相加题目描述思路实现 题目描述 You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single dig...

13. Roman to Integer罗马转整数题目描述思路实现 题目描述 Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L ...

56. Merge Intervals合并区间题目描述思路实现 题目描述 Given a collection of intervals, merge all overlapping intervals. Example 1: Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since ...

15. 3Sum题目描述思路实现 题目描述 Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Note: The soluti...

8. String to Integer (atoi）题目描述思路实现 题目描述 Implement atoi which converts a string to an integer. The function first discards as many whitespace characters as necessary until the first non-whitespace cha...

20. Valid Parentheses题目描述思路实现 题目描述 Given a string containing just the characters ‘(’, ‘)’, ‘{’, ‘}’, ‘[’ and ‘]’, determine if the input string is valid. An input string is valid if: Open brackets mus...

21. Merge Two Sorted Lists题目描述思路实现 题目描述 Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. Example: Input: 1-...

50. Pow(x, n）求x的n次幂题目描述思路实现 题目描述 Implement pow(x, n), which calculates x raised to the power n (xn). Example 1: Input: 2.00000, 10 Output: 1024.00000 Example 2: Input: 2.10000, 3 Output: 9.26100 Examp...

198.House Robber题目描述解题思路实现代码 题目描述 You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing e...

121.Best Time to Buy and Sell Stock题目描述解题思路实现代码 题目描述 Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transact...

141. Linked List Cycle题目描述解题思路实现代码 题目描述 Given a linked list, determine if it has a cycle in it. To represent a cycle in the given linked list, we use an integer pos which represents the position (0-in...

125. Valid Palindrome题目描述解题思路实现代码 题目描述 Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. Note: For the purpose of this problem, we define em...

122. Best Time to Buy and Sell Stock II题目描述解题思路实现代码 题目描述 Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may...

136. Single Number题目描述解题思路实现代码 题目描述 Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity....

1. Two Sum题目描述解题思路实现代码 题目描述 Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, an...

53. Maximum Subarray题目描述解题思路实现代码 题目描述 Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Example: Input: [-2,1,-3,...

322. Coin Change题目描述解题思路实现代码 题目描述 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 tha...

120.Triangle题目描述思路实现代码 题目描述 Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below. Example, given the following triangle [ ----- [...

70.Climbing Stairs）题目描述解题思路实现代码补充 题目描述 You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the ...

5. Longest Palindromic Substring题目描述思路实现 题目描述 Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000. Example 1: Input: “babad” Output: “bab...