int findPeakElement(int* nums, int numsSize){int l = 0, r = numsSize - 1;while (l < r) {int mid = (l + r) / 2;if (nums[mid] > nums[mid + 1])r = mid;elsel = mid + 1;}return l; } 原文：https://www.cnblogs.com/ganxiang/p/14183363.html
思路： 注意到给定字符串的长度是偶数，所以无论如何操作，所有可能的字符串也只有10 * 10 * n（n是字符串的长度）种，可以暴力枚举。 实现： 1 class Solution2 {3 public:4 string findLexSmallestString(string s, int a, int b)5 {6 int n = s.length();7 queue<string> q;8 q.push(s);9 unordered_set<string> st; 10 string res = s; 11 while (!q.empty()) 12 ...
LeetCode笔记 leetcode第一题就被虐翻，在此记录失败历程 num.size(） …nums的长度 return{i,j} …返回i,j return{} …返回空 unordered_map<int,int> …创建哈希表 auto …自动定义 hashtable.find(number) …hashtable中number的地址 hashtable.end() …hashtable尾项的地址 it->second …it所指的东西 if(a+b==c) …if后有括号
leetcode：#206 反转链表 题目详情 java实现 /*** Definition for singly-linked list.* public class ListNode {* int val;* ListNode next;* ListNode() {}* ListNode(int val) { this.val = val; }* ListNode(int val, ListNode next) { this.val = val; this.next = next; }* }*/ class Solution { //头插法public ListNode reverseList(ListNode head) {if (head == null) {return null;}ListNode revers...
抽象为把序列分成D段，求和最大的段的最小值 下界为最大值，上界为序列和，二分结果，每次去验证是否合适即可class Solution { public:int shipWithinDays(vector<int>& weights, int D) {int total = 0;int max_v = weights[0];for(int i = 0; i < weights.size(); i++) max_v = max(max_v, weights[i]), total += weights[i];int x = max_v, y = total;int cnt = 1, cnt_s;while(x < y){cnt_s = 0;cnt = 1;int mid = (x + y) / 2...
题目：（Stack）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 of each bar is 1, given height = [2,1,5,6,2,3]. The largest rectangle is shown in the shaded area, which has area = 10 unit. For example,Given height = [2,1,5,6,2,3],return 10. 题解：参考http://w...
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 (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.解题思路：本题原来做错的原因是我原以为只要找到最小值和最大值，相减就能得到最大的利润。但股票买卖是有顺序的，先买后卖。因此最小值必须是左边的，然后比较右边的...
LeetCode House Robber II题目思路思路来源于Discuss。 一是在Robber这题中的O(n)解法； 二是在Robber这题中，我们只需要分别考虑包含了nums[0]和nums[n-1]的情况即可。 注意这里的包含并不是说Robber一定要偷num[0]或nums[n-1]，只是说考虑进去的意思。代码#define max(a, b) ((a)>(b)?(a):(b))int rob(int* nums, int numsSize) {if (numsSize <= 0) return0;if (numsSize == 1) return nums[0];int evenMax, ooddMax, includ...
题目要求 算法分析利用栈解决.按索引遍历{ 如果栈为空,将索引入栈, 如果栈不空,判断,当前索引对应的温度是否比栈顶索引对应的温度高,{ 如果高则出栈,并计算索引差,所得结果存入返回数组对应的索引上,然后返回上一步重新比较栈顶元素和当前元素的大小 如果低则入栈。 }}代码展示（C#）publicclass Solution {publicint[] DailyTemperatures(int[] T) {int[] ret = newint[T.Length];Stack<int> stack = ne...
题目链接： https://leetcode.com/problems/remove-duplicates-from-sorted-array/?tab=Description 从有序数组中移除重复数字，并且返回不重复数字的个数 遍历操作： 可以使用新的for循环 for (int n : nums){} 每次进行对比，并且更新第一个遇到不相等的元素的下标为i对数组进行重新赋值操作 当数组长度大于1时，ans初值为1,当数组长度为0时，返回0 参考代码 ： package leetcode_50;/**** * @author pengfei_zheng* 移除有序数组...
Given a binary tree, return the preorder traversal of its nodes‘ values. For example: Given binary tree {1,#,2,3}, 12/3return [1,2,3].Note: Recursive solution is trivial, could you do it iteratively?/*** Definition for binary tree* struct TreeNode {* int val;* TreeNode *left;* TreeNode *right;* TreeNode(int x) : val(x), left(NULL), right(NULL) {}* };*/ class Solution { public:v...
Given a string S and a string T, count the number of distinct subsequences of T in S.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, "ACE" is a subsequence of "ABCDE" while "AEC" is not).Here is an example:S = "rabbbit", T = "rabbit"Return ...
Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 这个题考查的是KMP算法。先求特征向量，然后再进行匹配，确实能够大大提高效率。code例如以下：class Solution { public:char *strStr(char *haystack, char *needle) {if(strlen(haystack)==0&&strlen(needle)==0)return haystack;if(strlen(haystack)==0&&strlen(needle)!=0)return NULL;if(...
Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character ‘.‘.You may assume that there will be only one unique solution.A sudoku puzzle... ...and its solution numbers marked in red. 终于到了朝思暮想的sudoku solver了， 有了Valid Sudoku的基础，我知道了用哈希表可以很方便的判断冲突。思路还是遍历这个board，这次是找到为空的位置，然后对可能的结果集进...
回文数题目描述：给你一个整数 x ，如果 x 是一个回文整数，返回 true ；否则，返回 false 。回文数是指正序（从左向右）和倒序（从右向左）读都是一样的整数。例如，121 是回文，而 123 不是。示例说明请见LeetCode官网。来源：力扣（LeetCode）链接：https://leetcode-cn.com/probl...著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。解法一：前后遍历如果是负数，直接返回false；否则，将整数转化为字符串...