Method intToRoman

Leetcode/C++/IntToRoman.cpp:49–183

{
public:
    string intToRoman(int num) 
    {
        ios_base::sync_with_stdio(false);
        cin.tie(nullptr);
        cout.tie(nullptr);
        
        string ret= "";
        string str= to_string (num);
        
        int pow= str.size()-1;
        
        for (int i=0; i<str.size(); i++, pow--)
        {
            switch (pow)
            {
                case 3:
                    switch(str[i])
                    {
                        case '3':
                            ret+="M";
                        case '2':
                            ret+="M";
                        case '1':
                            ret+="M";
                            break;                           
                    }
                    
                    break;
                    
                case 2:
                    switch(str[i])
                    {
                        case '0':
                            break;
                        case '9':
                            ret+="CM";
                            break;
                        case '8':
                            ret+="D";
                        case '3':
                            ret+="CCC";
                            break;
                        case '7':
                            ret+="D";
                        case '2':
                            ret+="CC";
                            break;
                        case '6':
                            ret+="D";
                        case '1':
                            ret+="C";
                            break;
                        case '5':
                            ret+="D";
                            break;
                        case '4':
                            ret+="CD";
                            break;