Identify which of the following are declarations

1 :	extern int x;
2 :	float square ( float x ) { ... }
3 :	double pow(double, double);

#include<stdio.h>

int main()
{
    char far *near *ptr1;
    char far *far *ptr2;
    char far *huge *ptr3;
    printf("%d, %d, %d\n", sizeof(ptr1), sizeof(ptr2), sizeof(ptr3));
    return 0;
}

#include<stdio.h>

int main()
{
    char huge *near *far *ptr1;
    char near *far *huge *ptr2;
    char far *huge *near *ptr3;
    printf("%d, %d, %d\n", sizeof(ptr1), sizeof(*ptr2), sizeof(**ptr3));
    return 0;
}

#include<stdio.h>
typedef void v;
typedef int i;

int main()
{
    v fun(i, i);
    fun(2, 3);
    return 0;
}
v fun(i a, i b)
{
    i s=2;
    float i;
    printf("%d,", sizeof(i));
    printf(" %d", a*b*s);
}

/* myprog.c */
#include<stdio.h>
#include<stdlib.h>

int main(int argc, char **argv)
{
    int i, j=0;
    for(i=0; i<argc; i++)
        j = j+atoi(argv[i]);
    printf("%d\n", j);
    return 0;
}

#include<stdio.h>
double i;

int main()
{
    (int)(float)(char) i;
    printf("%d", sizeof((int)(float)(char)i));
    return 0;
}

#include<stdio.h>

int main()
{
    FILE *fs, *ft, *fp;
    fp = fopen("A.C", "r");
    fs = fopen("B.C", "r");
    ft = fopen("C.C", "r");
    fclose(fp, fs, ft);
    return 0;
}

#include<stdio.h>
#include<stdarg.h>
void varfun(int n, ...);

int main()
{
    varfun(3, 7, -11.2, 0.66);
    return 0;
}
void varfun(int n, ...)
{
    float *ptr;
    int num;
    va_start(ptr, n);
    num = va_arg(ptr, int);
    printf("%d", num);
}