leetcode-easy-math-13 Roman to Integer

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leetCode练题——13. Roman to Integer

1.题目13. Roman to Integer Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is…

[LeetCode&Python] Problem 13. Roman to Integer

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which i…

LeetCode记录之13——Roman to Integer

能力有限,这道题采用的就是暴力方法,也只超过了39%的用户.需要注意的就是罗马数字如果IXC的后一位比前一位大的采取的是减的方式. Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 给定一个罗马数字,将其转换为整数. 输入保证在1到3999之间. class Solution { public int romanToInt(Stri…

【leetcode❤python】13. Roman to Integer

#-*- coding: UTF-8 -*-#从前向后遍历罗马数字,#如果某个数比前一个数小,则加上该数.反之,减去前一个数的两倍然后加上该数###-----技术规则-----#-------------------------------------------------------------------------------------##1.相同的数字连写,所表示的数等于这些数字相加得到的数,例如:III = 3##2.小的数字在大的数字右边,所表示的数等于这些数字相加得到的数,例如…

Leetcode 13. Roman to Integer(水)

13. Roman to Integer Easy Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve i…

Leetcode#13. Roman to Integer（罗马数字转整数）

题目描述罗马数字包含以下七种字符:I, V, X, L,C,D 和 M. 字符数值 I 1 V 5 X 10 L 50 C 100 D 500 M 1000 例如, 罗马数字 2 写做 II ,即为两个并列的 1.12 写做 XII ,即为 X + II . 27 写做 XXVII, 即为 XX + V + II . 通常情况下,罗马数字中小的数字在大的数字的右边.但也存在特例,例如 4 不写做 IIII,而是 IV.数字 1 在数字 5 的左边,所表示的数等于大数 5 减小数 1 得到的数…

C# 写 LeetCode easy #13 Roman to Integer

13.Roman to Integer Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is writ…

13. Roman to Integer【leetcode】

Roman to Integer Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. public class Solution { public int romanToInt(String s) { if (s == null || s.length()==0) { return 0; } Map<Character, Intege…

【LeetCode】13. Roman to Integer (2 solutions)

Roman to Integer Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 解法一:非递归从左到右遍历每个字符,并记录上个字符来处理双字符情况即可. class Solution { public: int romanToInt(string s) { ; ; ; i < s.size(); i ++) { switch(…

《LeetBook》leetcode题解(13):Roman to Integer[E]

我现在在做一个叫<leetbook>的免费开源书项目,力求提供最易懂的中文思路,目前把解题思路都同步更新到gitbook上了,需要的同学可以去看看书的地址:https://hk029.gitbooks.io/leetbook/ 013. Roman to Integer 问题 Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. S…

[LeetCode] 13. Roman to Integer 罗马数字转化成整数

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which i…

【一天一道LeetCode】#13. Roman to Integer

一天一道LeetCode系列 (一)题目 Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. (二)解题和上一题相反,这题将罗马数字转换成整形数. 注意到 4,9,40,90,400,900这些特殊的数字的区别就不难写出代码了. class Solution { public: int romanToInt(string s) {…

LeetCode - 13. Roman to Integer - 思考if-else与switch的比较 - ( C++ ) - 解题报告

1.题目: 原题:Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. Subscribe to see which companies asked this questio 解析:给出一个罗马数字,要求把其转换为一个整数.输入范围在1到3999内. 罗马数字的规则如下: 罗马数字 I V X L C D M 代表的阿拉伯数字 1 5…

LeetCode题解(13)--Roman to Integer

https://leetcode.com/problems/roman-to-integer/ 原题: Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 思路: 关键是要搞清罗马数字规则.PS:不用考虑错误输入. 核心: 遍历一遍,相同字母合并成对应数,然后比较如果比它后面的小就减去,否则就加上.时间复杂度O(n). 具体解析: 基…

[leetcode] 13. Roman to Integer

如果某一个字母代表的数字大于上一个字母代表的数字小,那么加上这个数字,否则,减去两倍的前一个数字,然后加上这一位数字. public class Solution { private static char[][] chars = {{'I', 'V'}, {'X', 'L'}, {'C', 'D'}, {'M', 'O'}}; private static HashMap<Character, Integer> map = null; private static void init() {…

【LeetCode】13. Roman to Integer 罗马数字转整数

题目: Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 思路:与12题正好相反,罗马数字基本字符集:I V X L C D M (1, 5, 10, 50, 100, 500, 1000).思路是从字符串最低位开始匹配,累加相应字符对应的阿拉伯数字,要注意的就是I,X,L(1,10,100)要判断是在左还是在右,在左就减在右就加.…

【leetcode】13. Roman to Integer

题目描述: Given a roman numeral, convert it to an integer. 解题分析: 这道题只要百度一下转换的规则,然后着这解释写代码即可.实现上并没有什么难度,直接看代码即可具体代码: public class Solution { public int romanToInt(String s){ int[] value={1000,500,100,50,10,5,1}; char[] array ="MDCLXVI".toCharArray()…

Java [leetcode 13] Roman to Integer

问题描述: Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 解题思路: 上一题反过来就可以了,其实觉得这两道题很没有意思. 代码如下: public class Solution { public int romanToInt(String s) { int result; if (s == null || s.length()…

leetcode修炼之路——13. Roman to Integer

题目: Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 题目分析: 将罗马数字转换成阿拉伯数字,规则如下:罗马数字共有七个,即I(1),V(5),X(10),L(50),C(100),D(500),M(1000). 按照下面的规则可以表示任意正整数. 重复数次:一个罗马数字重复几次,就表示这个数的几倍.右加左减:在一个较大的罗马数…

LeetCode 13. Roman to Integer（c语言版）

题意: Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, whi…

LeetCode 13 Roman to Integer 解题报告

题目要求 Roman numerals are represented by seven different symbols: I, V, X, L, C, Dand M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, whi…

[leetcode]13. Roman to Integer罗马数字转整数

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which i…

13. Roman to Integer 罗马数字转化为阿拉伯数字（indexOf ()和 toCharArray()）easy

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which i…

[LeetCode] 13. Roman to Integer ☆☆

Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 解法: 只要考虑两种情况即可: 第一,如果当前数字是最后一个数字,或者之后的数字比它小的话,则加上当前数字第二,其他情况(即为4或者9,这种情况下才可能出现后面的罗马数字比前面的大),则减去这个数字 public class Solution { public int romanT…

LeetCode——13. Roman to Integer

一.题目链接:https://leetcode.com/problems/roman-to-integer/ 二.题目大意: 给定一个罗马数字,返回它的整数形式. 三.题解: 这道题与12题恰好相反,关键之处在于罗马数字的组成规律.首先,弄清楚每个罗马字母对应的数字大小: 实质上,对于一个罗马数字,只需遍历它的每个字母,然后将字母对应的数字逐一相加即可,但是如果后一个字母对应的数字比相邻的前一个字母对应的数字大的话,那么这两个字母对应的数值实际上是大的数字减去小的数字,而不是两个数字的和.举个例…