166. 分数到小数 给定两个整数,分别表示分数的分子 numerator 和分母 denominator,以字符串形式返回小数. 如果小数部分为循环小数,则将循环的部分括在括号内. 示例 1: 输入: numerator = 1, denominator = 2 输出: "0.5" 示例 2: 输入: numerator = 2, denominator = 1 输出: "2" 示例 3: 输入: numerator = 2, denominator = 3 输出…

分数到小数 给定两个整数,分别表示分数的分子 numerator 和分母 denominator,以字符串形式返回小数. 如果小数部分为循环小数,则将循环的部分括在括号内. 示例 1: 输入: numerator = 1, denominator = 2 输出: "0.5" 示例 2: 输入: numerator = 2, denominator = 1 输出: "2" 示例 3: 输入: numerator = 2, denominator = 3 输出: &qu…

手动排除特殊情况: 对于一般情况,使用位运算和加减法来计算除法,使用sign记录结果符号:(这部分为leetcode 29题的答案) 使用hashmap来记录循环体出现的开始位置(如果有的话),使用flag记录有无循环体出现: class Solution { public: string fractionToDecimal(int numerator, int denominator) { ||denominator==-)){ if(numerator==INT_MIN){ ?"; } if…

Given two integers representing the numerator and denominator of a fraction, return the fraction in string format. If the fractional part is repeating, enclose the repeating part in parentheses. For example, Given numerator = 1, denominator = 2, retu…

592. 分数加减运算 给定一个表示分数加减运算表达式的字符串,你需要返回一个字符串形式的计算结果. 这个结果应该是不可约分的分数,即最简分数. 如果最终结果是一个整数,例如 2,你需要将它转换成分数形式,其分母为 1.所以在上述例子中, 2 应该被转换为 2/1. 示例 1: 输入:"-1/2+1/2" 输出: "0/1" 示例 2: 输入:"-1/2+1/2+1/3" 输出: "1/3" 示例 3: 输入:"1/…

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers. Ensure that numbers within the set are sorted in ascending order. Example 1…

Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can find by performing this transformation. For example: Given "aacecaaa", return "aaacecaaa&qu…

Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same le…

Design a data structure that supports the following two operations: void addWord(word)bool search(word) search(word) can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter.…

There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair: [0,1] Given the total number of courses and a l…

此小工具类主要用于数值四舍五入.数值格式化输出,很简单,若想深入研究,敬请自行查阅 BigDecimal 或 DecimalFormat 的 API,BigDecimal.setScale(位数,四舍五入法)中四舍五入法有如下 7 种: 1. ROUND_UP:远离零方向舍入.向绝对值最大的方向舍入,只要舍弃位非0即进位. 2. ROUND_DOWN:趋向零方向舍入.向绝对值最小的方向输入,所有的位都要舍弃,不存在进位情况. 3. ROUND_CEILING:向正无穷方向舍入.向正最大方向靠拢.…

分数转小数,要求输出循环小数 如2 3 输出0.(6) 弗洛伊德判环的原理是在一个圈里,如果一个人的速度是另一个人的两倍,那个人就能追上另一个人.代码中one就是速度1的人,而two就是速度为2的人. Fraction to Recurring Decimal可以使用弗洛伊德判环,不同的是要找到循环出现的起始点,因此会比单单判断是否循环出现的题要难一点,代码要长一点,但是它比是用map的实现会更快. 要做出这道题有几个注意点: 1)对于整数的求余和整除运算要注意,特别负数的求余运算, 可以参考…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most k transactions. 解题思路: https://leetcode.com/discuss/18330/is-it-best-solution-with-o-n-o-1…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. The array may contain duplicates. 解题思路: 参考Java for LeetCode 081 Search in Rotated Sorted Array II J…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 解题思路: 本题和Java for LeetCode 033 Search in Rotated S…

The set [1,2,3,…,n] contains a total of n! unique permutations. By listing and labeling all of the permutations in order, We get the following sequence (ie, for n = 3): "123" "132" "213" "231" "312" "…

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example, Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ]] 解题思路: 参考Java for LeetCode 054 Spiral Matrix,修改下…

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that the intervals were initially sorted according to their start times. Example 1: Given intervals [1,3],[6,9], insert and merge…

Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maximum jump length at that position. Determine if you are able to reach the last index. For example: A =…

Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the following unique permutations: [1,1,2], [1,2,1], and [2,1,1]. 解题思路一: 发现Java for LeetCode 046 Permutations自己想多了,代码直接拿来用…

Implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. '*' Matches any sequence of characters (including the empty sequence). The matching should cover the entire input string (not partial). The function p…

Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", which has length = 2. Another example is &…

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 解题思路一: 之前我们有mergeTwoLists(ListNode l1, ListNode l2)方法,直接调用的话,需要k-1次调用,每次调用都需要产生一个ListNode[],空间开销很大.如果采用分治的思想,对相邻的两个ListNode进行mergeTwoLists,每次将规模减少一半,直到…

4种方法,都是四舍五入,例: import java.math.BigDecimal; import java.text.DecimalFormat; import java.text.NumberFormat; public class format { double f = 111231.5585; public void m1() { BigDecimal bg = new BigDecimal(f); double f1 = bg.setScale(2, BigDecimal.ROUND…

P1530 分数化小数 Fractions to Decimals 103通过 348提交 题目提供者该用户不存在 标签USACO 难度普及/提高- 提交  讨论  题解 最新讨论 暂时没有讨论 题目描述 写一个程序,输入一个形如N/D的分数(N是分子,D是分母),输出它的小数形式. 如果小数有循环节的话,把循环节放在一对圆括号中. 例如, 1/3 =0.33333333写成0.(3), 41/333 = 0.123123123...写成0.(123), 用xxx.0 等表示整数. 典型的转化例…

用java具体代码实现分数(即有理数)四则运算 1,背景 Java老师布置了一个关于有理数运算的题目,因为参考书上有基本代码,所以自己主要是对书上代码做了一点优化,使其用户交互性更加友好以及代码封装性更强 2,说明: 分数也称作有理数,是我们很熟悉的一种数.有时希望程序能对分数进行四则运算,而且两个分数四则运算的结果仍然是分数.下面是具体实现 3,java代码具体实现 3.1 运算类封装 package Rational; import java.util.StringTokenizer; /*…

/* 分数化小数 输入正整数a,b,c,输出a/b的小数形式.精确到小数点后C位.a,b<=10^6,c<=10^6. 输入包含多组数据,结束标记为a=b=c=0 样例输入: 1 6 4 0 0 0 样例输出: Case 1: 0.1667 */ #include <iostream> #include<iomanip> // C++格式控制头文件 using namespace std; int main(){ int a, b, c; int cases = 0;…

分数化小数 ①我的程序 #include<iostream>using namespace std;int main(void){ int a,b,c,kase=0; while(scanf("%d%d%d",&a,&b,&c)!=EOF&&(a||b||c)) { printf("Case %d: %.cf\n",++kase,(double)a/b); } return 0;} 测试 看其他数据会输出什么结果…

java用double和float进行小数计算精度不准确 大多数情况下,使用double和float计算的结果是准确的,但是在一些精度要求很高的系统中或者已知的小数计算得到的结果会不准确,这种问题是非常严重的. <Effective Java>中提到一个原则,那就是float和double只能用来作科学计算或者是工程计算,但在商业计算中我们要用java.math.BigDecimal,通过使用BigDecimal类可以解决上述问题,java的设计者给编程人员提供了一个很有用的类BigDecim…