returning address of local variable or temporary

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

int *a();
char *b();
int *aa();

int main(void)
{
    int *p = a();
    int i;

    for(i = 0; i < 5; i++)
        printf("%d ", p[i]);
    return 0;
}

int *a(){
    int p[] = {1,2,3,4,5};
    return p;
}

char *b(){
    char *s = "test";
    return s;
}

int *aa(){
    int *a = malloc(sizeof(int));
    *a = 10;
    return a;
}


Just for fun...