lc 399 Evaluate Division 399 Evaluate Division Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does…

Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. Example:Given a / b =…

我是链接 看到这道题,2个点和一个权值,然后想到图,但是leetcode就是这样,没给数据范围,感觉写起来很费劲,然后就开始用图来做,添加边的时候,注意正向边和反向变,然后查询的时候,先判断2个点是否都出现,然后判断是不是自己到自己,最后用dfs或者bfs到图里面去搜索,第一次交的时候,忘记用vis标记访问过的点,导致tle,加上之后,就ac了,套路一般吧,不知道还有什么trick. double dfs(vector<vector<pair<int, double> > &…

Evaluate Division题解 原创文章,拒绝转载 题目来源:https://leetcode.com/problems/evaluate-division/description/ Description Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/delete-and-earn/description/ 题目描述 Equations are given in the format A / B = k, where A and B are variables represented as strings, and k i…

题目如下: Equations are given in the format A / B = k, whereA and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. Example:Given a /…

图像题,没觉得有什么简单的办法,貌似可以用Union Find来解. 感觉有2种思路,一种是先全部构建好每2个点的weight,然后直接遍历queires[][]来抓取答案. 一种是只构建简单的关系图,然后通过DFS来一一找寻要求的答案. 做了一会好他妈的麻烦,最后参考了(http://blog.csdn.net/yeqiuzs/article/details/52506433) 用的是第二种. 需要注意,不存在 优先于 相等 eg : x/x = -1.0, not 1.0, if x DNE…

Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. Example:Given a / b =…

Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. Example: Given a / b =…

Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Note: Division between two integers should truncate toward zero. The given RPN expression…

   一.问题描述 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", "*&…

Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Note: Division between two integers should truncate toward zero. The given RPN expression…

Evaluate Reverse Polish Notation 题目描述: 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", "+"…

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", "*"] -&g…

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", "*"] -&g…

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", "*"] -&g…

#define ADDITION '+' #define SUBSTRACTION '-' #define MULTIPLICATION '*' #define DIVISION '/' class Solution { public: set<char> tokenSet{'+', '-', '*', '/'}; stack<int> num; int evalRPN(vector<string> &tokens) { for (auto &token…

Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. Example:Given a / b =…

一.题目链接:https://leetcode.com/problems/evaluate-reverse-polish-notation/ 二.题目大意: 给定后缀表达式,求出该表达式的计算结果. 三.题解: 对于这道题目,首先观察后缀表达式(逆波兰表达式)的特点,那就是运算符在操作数的后面,所以每遇到一个运算符,只需找到它之前的最近的两个数字作为操作数,然后求出的结果作为一个新的操作数.很显然,可以使用一个栈来存储操作数,每遇到运算符从栈中取出顶端的两个数运算即可,运算结果再入栈.代码如下:…

Evaluate Reverse Polish Notation Total Accepted: 24595 Total Submissions: 123794My Submissions Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expres…

lc 238 Product of Array Except Self 238 Product of Array Except Self Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i]. Solve it without divis…

399. 除法求值 给出方程式 A / B = k, 其中 A 和 B 均为代表字符串的变量, k 是一个浮点型数字.根据已知方程式求解问题,并返回计算结果.如果结果不存在,则返回 -1.0. 示例 : 给定 a / b = 2.0, b / c = 3.0 问题: a / c = ?, b / a = ?, a / e = ?, a / a = ?, x / x = ? 返回 [6.0, 0.5, -1.0, 1.0, -1.0 ] 输入为: vector<pair<string, stri…

lc 292 Nim Game 292 Nim Game You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. You will tak…

原题地址 基本栈操作. 注意数字有可能是负的. 代码: int toInteger(string &s) { ; ] == '-' ? true : false; : ; i < s.length(); i++) { res *= ; res += s[i] - '; } return negative ? -res : res; } int compute(int a, int b, string sign) { ]) { case '+': return a + b; case '-':…

很简单的一道题,定义一个栈保留操作数,遇操作符则弹出运算即可. bool isOperator(string &op) { //注意用法 && string("+-*/").find(op) != string::npos; } int evalRPN(vector<string> &tokens) { stack<string> s; for (auto token : tokens) { if (!isOperator(tok…

lc 746 Min Cost Climbing Stairs 746 Min Cost Climbing Stairs On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed). Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach t…

lc 684 Redundant Connection 684 Redundant Connection In this problem, a tree is an undirected graph that is connected and has no cycles. The given input is a graph that started as a tree with N nodes (with distinct values 1, 2, ..., N), with one addi…

lc 730 Count Different Palindromic Subsequences 730 Count Different Palindromic Subsequences Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S i…

lc 516 Longest Palindromic Subsequence 516 Longest Palindromic Subsequence Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1: Input: "bbbab" Output: 4 One pos…

lc 215 Kth Largest Element in an Array 215 Kth Largest Element in an Array Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. For example, Given [3,2,1,5,6,4]…