[C] Radice digitale e ricorsività

[MacApp]

Prova con:

/*
* Compiled and tested with:
* i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build 5367)
* 
* input: 65536
* output: 7
*
*/

#include <stdio.h>
#include <stdlib.h>

int somma(int);

int main() {
    int a;
    scanf("%i",&a);
    printf("%i\n",somma(a)); 
    return 0;
}

int somma(int n) {    
    if (n < 10)
        return n;
    else
        n = somma (n%10 + somma(n/10));
    return n; 
}