链接:https://leetcode-cn.com/problems/first-missing-positive 分析: 要求时间复杂度为O(N),并且只能使用常数级别的空间 根据抽屉原理:数组的长度n,则答案最大只能是n+1; 可以使用hash函数将答案空间映射到长度为n+1的数组上,再遍历数组找到最小的没出现的正整数。 为实现常数空间复杂度,可以使用原数组的空间...
* MyHashMap obj = new MyHashMap(); * obj.put(key,value); * int param_2 = obj.get(key); * obj.remove(key); */ 04 第三种解法 使用单链表,此解法是参考至讨论区。传送门:https://leetcode.com/problems/design-hashmap/discuss/227081/Java-Solutions classMyHashMap{/** Initialize your da...
https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ https://leetcode.com/problems/minimum-depth-of-binary-tree/ https://leetcode.com/problems/populating-next-right-pointers-in-each-node/ https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/ https://le...
AI代码解释 publicclassSolution{publicbooleanisStrobogrammatic(String num){HashMap<Character,Character>map=newHashMap<Character,Character>();map.put('1','1');map.put('0','0');map.put('6','9');map.put('9','6');map.put('8','8');int left=0,right=num.length()-1;while(left<=...
用HashMap存储某个count第一次出现的位置,后续判断是否存在这个key,就可以计算maxLen了 LeetCode560 Medium 和为K的子数组 leetcode-cn.com/problem LeetCode848 Medium 字母移位 leetcode-cn.com/problem 从后往前处理。 12.子数组类问题 特点:i是起始位置 j是终点位置 LeetCode718 最长重复子数组 leetcode-cn...
Answers for the leetcode problems Solutions MAY vary with offical LeetCode Solutions. PLEASE do a pull request for more elegant solutions(New Issue Request Template, make sure to read it!). Tips for beginners: If you are spending too much time on a problem, look and interpret the solutions...
一遍hashmap 解法 代码语言:javascript 代码运行次数:0 运行 AI代码解释 class Solution { public int[] twoSum(int[] nums, int target) { /* 使用hashmap */ int[] res = new int[2]; Map<Integer,Integer> map = new HashMap<Integer,Integer>(); for(int i = 0 ; i<nums.length;i++){ ...
705 Design HashSet Easy Python 706 Design HashMap Easy Rust 707 Design Linked List Medium Python 709 To Lower Case Easy Go 712 Minimum ASCII Delete Sum for Two Strings Medium JavaScript Python 713 Subarray Product Less Than K Medium JavaScript Python 714 Best Time to Buy and Sell Stock with...
LeetCode Problems 一. 目录 二.分类 Array String Two Pointers Linked List Stack Tree Dynamic Programming Backtracking Depth First Search Breadth First Search Binary Search Math Hash Table Sort Bit Manipulation Union Find Sliding Window Segment Tree Binary Indexed Tree ♥️ Thanks LeetCode in Go Le...
Integer> 统计每个数值出现的频次int[] nums = {4,1,2,1,2}; Map<Integer, Integer> cntMap =newHashMap<>();for(intnum : nums) {// Verboseif(!cntMap.containsKey(num)) { cntMap.put(num,0); } cntMap.put(num, cntMap.get(num) +1);// ObviouscntMap.put(num, cntMap.getOrDefault...