Comparing two strings and diiferentiating if they are numbers or characters!

#include <iostream>

#include <cctype>

#include <cstdlib>

#include <cstring>

using namespace std;

void check(char *a, char *b,int (*cmp)(const char*, const char *));

int numcmp(const char *a, const char *b);

int main (){

    char s1[80], s2[80];

    gets(s1);

    gets(s2);

    if(isalpha(*s1)){

        check(s1,s2,strcmp);

    } else {

        check(s1,s2,numcmp);

    }

    return 0;

}

void check(char *a, char *b,int (*cmp)(const char*, const char *)){

    cout << "Testing for equality."<<endl;

    if(!(*cmp)(a,b)){

        cout << "Equal";

    }else {

        cout << "Not Equal";

    }  

}

int numcmp(const char *a, const char *b){

    if(atoi(a)==atoi(b)){

        return 0;

    } else {

        return 1;

    }

}