[NOIP2007 提高组] 字符串的展开

#include <iostream>
using namespace std;
int p1, p2, p3;
void ff(char a)
{
    if (p1 == 3)
        a = '*';
    else if (p1 == 2)
    {
        if ('a' <= a && a <= 'z')
            a = a - 'a' + 'A';
    }
    else
    {
        if ('A' <= a && a <= 'Z')
            a = a - 'A' + 'a';
    }
    for (int i = 0; i < p2; i++)
        cout << a;
}
void f(char a, char b)
{
    string s = "";
    if (b <= a)
    {
        cout << '-';
        return;
    }
    if (('0' <= a && a <= '9' && '0' <= b && b <= '9') ||
        ('a' <= a && a <= 'z' && 'a' <= b && b <= 'z') ||
        ('A' <= a && a <= 'Z' && 'A' <= b && b <= 'Z'))
    {
        if (p3 == 1)
        {
            for (char x = a + 1; x <= b - 1; x++)
                ff(x);
        }
        else
        {
            for (char x = b - 1; x >= a + 1; x--)
                ff(x);
        }
    }
    else
    {
        cout << '-';
        return;
    }
}
int main()
{
    string s;
    cin >> p1 >> p2 >> p3;
    cin >> s;
    for (int i = 0; i < s.length(); i++)
    {
        if (s[i] == '-')
        {
            if (i != 0 && i != s.length() - 1)
                f(s[i - 1], s[i + 1]);
            else
                cout << '-';
        }
        else
            cout << s[i];
    }
    return 0;
}