标签:解题思路 with represent NPU ring res div int however
算法描述:
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 is simply X
+ II
. The number twenty seven is written as XXVII
, which is XX
+ V
+ II
.
Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII
. Instead, the number four is written as IV
. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX
. There are six instances where subtraction is used:
I
can be placed before V
(5) and X
(10) to make 4 and 9. X
can be placed before L
(50) and C
(100) to make 40 and 90. C
can be placed before D
(500) and M
(1000) to make 400 and 900.Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999.
Example 1:
Input: 3 Output: "III"
Example 2:
Input: 4 Output: "IV"
Example 3:
Input: 9 Output: "IX"
Example 4:
Input: 58 Output: "LVIII" Explanation: L = 50, V = 5, III = 3.
Example 5:
Input: 1994 Output: "MCMXCIV" Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
解题思路:细节题,考虑数字之间的对应关系。
string intToRoman(int num) { vector<string> ch = {"I","IV","V","IX","X","XL","L","XC","C","CD","D","CM","M"}; vector<int> value = {1,4,5,9,10,40,50,90,100,400,500,900,1000}; string results = ""; for(int i =value.size()-1; i >=0; i--){ while(num >= value[i]){ num -= value[i]; results += ch[i]; } } return results; }
标签:解题思路 with represent NPU ring res div int however
原文地址:https://www.cnblogs.com/nobodywang/p/10326626.html