LeetCode "Integer to Roman"

char dict[] = {'I', 'V', 'X', 'L', 'C', 'D', 'M'};
class Solution 
{    
public:
    string pattern(int v, int level)
    {
        int offset = int(log10(level)) * 2;
        char *p = dict + offset;
        
        string ret;
        switch(v)
        {
        case 1:
        case 2:
        case 3:
            for(int i = 0; i < v; i++)    ret += *p;
            break;
        case 4:
            ret += *(p);            
        case 5:
            ret += *(p+1);
            break;
        case 6:
        case 7:
        case 8:
            ret += *(p+1);
            for(int i = 0; i < (v - 5); i ++) ret += *(p);
            break;
        case 9:
            ret += *(p);
        case 10:
            ret += *(p+2);
            break;
        }
        return ret;
    }
    string intToRoman(int num) 
    {
        string ret;
        
        int base = 10000;
        while(num)
        {    
            base /= 10;
            ret += pattern(num/base, base);            
            if (base > 1)    num %= base;
            if (base == 1) break;            
        }

        return ret;
    }
};