stack = [] 2. Python中加入元素到栈,和从栈中弹出元素的方法: #加入栈 stack.append(char) #弹出栈 s[i] = stack.pop() 解法3:使用range class Solution: def reverseString(self, s: List[str]) -> None: n = len(s) for i in range(n//2): s[i], s[n-i-1] = s[n-i-1], ...
leetcode:栈 1. evaluate-reverse-polish-notation Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are+,-,*,/. Each operand may be an integer or another expression. Some examples: ["2", "1", "+", "3", "*"] -> ((2 + 1) * 3) -> 9 [...
该模式看起来是这样的：1．初始化。a）使用 HashMap 将图（graph）存储到邻接的列表中；b）为了查找...
You need to reduce multiple spaces between two words to a single space in the reversed string. Follow up: For C programmers, try to solve itin-placeinO(1) space. 用stack 做 publicclassSolution {publicString reverseWords(String s) {if(s ==null|| s.length() == 0){returns; } Stack<...
动态规划 15. 排序算法 16. 树和链表结合 17. 树的重新构建 18. 位运算 19. 字符串 20. stack ...
next == null) { return head; } ListNode newHead = reverseList(head.next); head.next.next = head; head.next = null; return newHead; } 对于迭代法也是类似的,但需要额外考虑一下,究竟应该保存链表的哪些节点。这里我们要保存的是它的前一个和后一个。这是因为前一个是它所要指向的位置(反转了...
reverse(); buffer.insert(0, stack.pop()); } else { buffer.append(ch); } } return buffer.toString(); } //双指针 public String reverseParentheses02(String s) { StringBuilder builder = new StringBuilder(s); while (true) { //end和prev分别得到最中间的括号下标 int end = builder.indexOf(...
publicStringreverseVowels(String s){if(s == null || s.trim().length() <=1) {returns ; } Stack<Character> stack =newStack<Character>();char[] arr = s.toCharArray();for(inti=0; i<arr.length; i++) {charch = arr[i];if(ch =='a'|| ch =='e'|| ch =='i'|| ch =='...
1#defineADDITION '+'2#defineSUBSTRACTION '-'3#defineMULTIPLICATION '*'4#defineDIVISION '/'567classSolution {8public:9set<char> tokenSet{'+','-','*','/'};10stack<int>num;11intevalRPN(vector<string> &tokens) {12for(auto &token : tokens) {13auto iter = tokenSet.find( token[token...
新手热身第11题 - 图文版-LeetCode 7M Reverse Integer 翻转整数;视频版-B站,视频版-知乎 新手热身第12题 - 图文版-LeetCode 9E Palindrome Number 回文数字判断;视频版-B站;视频版-知乎 新手热身第13题 - 图文版-王几行XING:素数(质数)的筛选和输出 ...