12. Integer to Roman

模拟模拟模拟

class Solution {
public:
    string intToRoman(int num) {
        int Cnt = 0;
        string ans = "";
        while (num) {
            ++Cnt;
            int temp=num % 10;
            num/=10;
            string k = "";
            if (temp > 5) {
                if (temp == 9){
                    if (Cnt == 1)k = "IX";
                    else if (Cnt == 2)k = "XC";
                    else k = "CM";
                }
                else {
                    if(Cnt==1)k = "V";
                    else if (Cnt == 2)k = "L";
                    else k = "D";
                    while (temp - 5) {
                        --temp;
                        if(Cnt==1)k += "I";
                        else if (Cnt == 2)k += "X";
                        else k += "C";
                    }
                }
            }
            else if (temp < 5) {
                if (temp == 4){
                    if(Cnt==1)k = "IV";
                    else if (Cnt == 2)k = "XL";
                    else k = "CD";
                }
                else {
                    while (temp) {
                        --temp;
                        if(Cnt==1)k += "I";
                        else if (Cnt == 2)k += "X";
                        else if (Cnt == 3)k += "C";
                        else k += "M";
                    }
                }
            }
            else {
                if(Cnt==1)k = "V";
                else if (Cnt == 2)k = "L";
                else k = "D";
            }
            ans = k + ans;
        }
        return ans;
    }
};