Số siêu xấu

#include <iostream>
#include <math.h>

using namespace std;
int Ghep_So(int Len, int sieuXau[], int size);
int NumberLen(int n);
int Supper_Ugly_Number(int n);
int n;

int main()
{
    cout << "Nhap n = ";
    cin >> n;
    if (n >= 0 && n <= 10000) cout << "\nSo sieu sau = "<<Supper_Ugly_Number(n);
    else cout << "So ban nhap khong hop le";
}
int Supper_Ugly_Number(int n)
{
    if (n<=10) {
        if (n%2 == 0) return n+1;
        else return n+2;
    } else if (n==99) return 111;
    else if (n==999) return 1111;
    else if (n==9999) return 11111;

    int Len = NumberLen(n);
    int Truc = roundf((float)Len/2);
    int sieuXau[Truc], soHang[Len];
    int so_tam = n;
    for (int i = Len-1; i >=0; i--)
    {
        soHang[i] = so_tam%10;
        so_tam = so_tam / 10;
    }
    for (int i = 0; i < Truc; i++)
    {
        if (soHang[i] % 2 == 0) {
            sieuXau[i]=soHang[i]+1;
            for (int j = i+1; j < Len; j++) {
                sieuXau[j]= 1;
            }
            break;
        }
        else sieuXau[i]=soHang[i];
    }
    int number = Ghep_So(Len,sieuXau,Truc);
    if (number <= n) {
        sieuXau[Truc-1] += 2;
        for (int i = Truc-1; i>=0; i--) {
            if (sieuXau[i]>9) {
                sieuXau[i]=1;
                for (int j = i-1; j >=0; j--) {
                    sieuXau[j] += 2;
                    if (sieuXau[j] >9) sieuXau[j]=1;
                    else break;
                }
                break;
            } else break;
        }
        number = Ghep_So(Len,sieuXau,Truc);
    }
    return number;
}
int Ghep_So(int Len, int sieuXau[], int size)
{
    int number = 0;
    if (Len % 2 == 0) {
        for (int i = 0; i < size; i++) number += sieuXau[i]*pow(10,i);
        int so_tam = 0;
        for (int i = 0; i < size; i++) so_tam += sieuXau[i]*pow(10,size-i-1);
        so_tam = so_tam * pow(10,size);
        number += so_tam;
    } else {
        for (int i = 0; i < size-1; i++) number += sieuXau[i]*pow(10,i);
        int so_tam = 0;
        for (int i = 0; i < size; i++) so_tam += sieuXau[i]*pow(10,size-i-1);
        so_tam = so_tam * pow(10,size-1);
        number += so_tam;
    }
    return number;
}
int NumberLen(int n)
{
    int so_tam = n;
    int number = 0;
    do {
        number++;
        so_tam /= 10;
        if (so_tam == 0) break;
    } while (1);
    return number;
}