【LeetCode】11. Integer to Roman

 

 

 

Given an integer, convert it to a roman numeral.

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

仔细理解罗马数的规则，把IV IX等也作为基本元素列入对应表中。然后每次选择能表示的最大值，把对应的字符串连起来。直到剩下的数=0为止。

public class Solution {
    public String intToRoman(int num) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        String str="";    
        String symbol[] = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};    
        int value[] = {1000,900,500,400, 100, 90,  50, 40,  10, 9,   5,  4,   1};   
        for(int i=0;num!=0;++i)  
        {  
            while(num>=value[i])  
            {  
                num-=value[i];  
                str+=symbol[i];  
            }  
        }  
        return str;  
    }
}