Leetcode-integer to Roman

Question:

Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999.

 

Question Analysis:

After reading the questions for a long time, I couldn't understand what Roman numeral was. So I checked it online and found out what it was, indicating that it was speechless.

Simulation questions:

Basic Characters	I	V	X	L	C	D	M
Meanings of corresponding Arabic numerals	1	5	10	50	100	500	1000

1. For the same number, the number is equal to the sum of the numbers, for example, III = 3;

2. If a small number is on the left of a large number, the number is equal to the number reduced by a large number, for example, IV = 4; ix = 9;

3. If a small number is on the right of a large number, the number is equal to the value of a large number plus a small number. For example, Vi = 6; xi = 11;

Code:

class Solution{public:    void setDigit(string &res,int n,char a,char b,char c){           if(n<4){                 for(int i=0;i<n;i++){                         res.push_back(a);                }           }                      else if(n==4){                 res.push_back(a);                 res.push_back(b);           }                      else if(n==5){                 res.push_back(b);           }                      else if(n>5 && n<9){                  res.push_back(b);                  for(int i=5;i<n;i++){                        res.push_back(a);                  }          }                    else if(n==9){              res.push_back(a);              res.push_back(c);          }    }        string intToRoman(int num){          int a1=(num/1000)%10,a2=(num/100)%10,a3=(num/10)%10,a4=num%10;          setDigit(res,a1,‘M‘,‘?‘,‘?‘);          setDigit(res,a2,‘C‘,‘D‘,‘M‘);          setDigit(res,a3,‘X‘,‘L‘,‘C‘);          setDigit(res,a4,‘I‘,‘V‘,‘X‘);          return res;    }};

Refer to what someone else wrote...

Leetcode-integer to Roman