Exista doua metode (cel putin...).
Metoda 1 (ceva mai simplu, dar are nevoie de for):
#include <iostream>
using namespace std;
int main()
{
char a[100], b;
cin.get(a, 100);
cin >> b;
for (int i=0; a[i]; i++)
if (a[i]==b)
{
cout << i;
break;
}
return 0;
}
Metoda 2 (nu are nevoie de for):
#include <iostream>
#include <cstring>
using namespace std;
int main()
{
char a[100], b;
cin.get(a, 100);
cin >> b;
cout << strchr(a,b)-a;
return 0;
}