Point out the error in the program.

#include<stdio.h>
#define MAX 128

int main()
{
    char mybuf[] = "India";
    char yourbuf[] = "CURIOUSTAB";
    char const *ptr = mybuf;
    *ptr = 'a';
    ptr = yourbuf;
    return 0;
}

#include<stdio.h>
int X=40;
int main()
{
    int X=20;
    printf("%d\n", X);
    return 0;
}

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

int main(int argc, char **argv)
{
    int i;
    for(i=1; i<=3; i++)
        printf("%u\n", &argv[i]);
    return 0;
}

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

int main()
{
    int *p;
    p = (int *)malloc(20); /* Assume p has address of 1314 */
    free(p);
    printf("%u", p);
    return 0;
}

#include<stdio.h>

int main()
{
    int arr[2][2][2] = {10, 2, 3, 4, 5, 6, 7, 8};
    int *p, *q;
    p = &arr[1][1][1];
    q = (int*) arr;
    printf("%d, %d\n", *p, *q);
    return 0;
}

#include<stdio.h>

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

/* sample.c */
#include<stdio.h>

int main(int argc, char *argv[])
{
    printf("%s\n", argv[0]);
    return 0;
}