MAGDB的博客

原题：Write a function to find the longest common prefix string amongst an array of strings.If there is no common prefix, return an empty string “”.Example 1:Input: ["flower","flow","flight"]Output:..

原题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 each of them is that adjacent ho...

原题Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree [3,9,20,null,null,15...

原题Given two binary trees, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical and the nodes have the same value.Example...

快速排序不清晰思路class Solution {public: void swap(int& a,int& b) { int c = a; a = b; b = c; } void quickSort(vector<int>& nums,int left,int right)...

原题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 top?Note: Given n will be a positiv...

原题Given an array where elements are sorted in ascending order, convert it to a height balanced BST.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of t...

原题Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.Note: A leaf is a node with no childr...

原题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 transaction (i.e., buy one and sell one share of the stock...

原题Given a sorted linked list, delete all duplicates such that each element appear only once.Example 1:Input: 1->1->2Output: 1->2Example 2:Input: 1->1->2->3->3Output: 1-&gt...

原题：Implement strStr().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: 2Example ...

原题：Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.Symbol ValueI 1V 5X 10L 50C 100D ...

原题：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,-3,4,-1,2,1,-5,4],Output: 6Explanat...

原题：Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.Do not allocate extra space for another array, you must do this by modi...

原题：Given a string s consists of upper/lower-case alphabets and empty space characters ’ ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is def...

原题：Given an array nums and a value val, remove all instances of that value in-place and return the new length.Do not allocate extra space for another array, you must do this by modifying the input a...

//二分法 超时了不知道对错int mySqrt(int x){long long i = 0;long long j = (x + 1)/2;while (i <= j){ long long mid = (i + j) / 2; long long sq = mid * mid; if (sq == x) return mid; else if...

char* addBinary(char* a, char* b) { int lena = strlen(a), lenb = strlen(b), carry = 0; int lenc = lena > lenb?lena:lenb; char * c = malloc(lenc+2); c[lenc+1] = '\0'; whi...

原题：Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicates in the array...

原题In a town, there are N people labelled from 1 to N. There is a rumor that one of these people is secretly the town judge.If the town judge exists, then:The town judge trusts nobody.Everybody (e...