Point out the error in the program?

#include<stdio.h>

int main()
{
    struct emp
    {
        char n[20];
        int age;
    };
    struct emp e1 = {"Dravid", 23};
    struct emp e2 = e1;
    if(e1 == e2)
        printf("The structure are equal");
    return 0;
}

#include<stdio.h>

int main()
{
    struct emp
    {
        char name[20];
        float sal;
    };
    struct emp e[10];
    int i;
    for(i=0; i<=9; i++)
        scanf("%s %f", e[i].name, &e[i].sal);
    return 0;
}

#include<stdio.h>

int main()
{
    struct bits
    {
        float f:2;
    }bit;

    printf("%d\n", sizeof(bit));
    return 0;
}

#include<stdio.h>

int main()
{
    union a
    {
        int i;
        char ch[2];
    };
    union a z1 = {512};
    union a z2 = {0, 2};
    return 0;
}

struct emp
{
    int ecode;
    struct emp e;
};

typedef struct data mystruct;
struct data
{
    int x;
    mystruct *b;
};

#include<stdio.h>

int main()
{
    struct emp
    {
        char name[25];
        int age;
        float bs;
    };
    struct emp e;
    e.name = "Suresh";
    e.age = 25;
    printf("%s %d\n", e.name, e.age);
    return 0;
}

struct emp
{
    int ecode;
    struct emp *e;
};

#include<stdio.h>

int main()
{
    struct a
    {
        float category:5;
        char scheme:4;
    };
    printf("size=%d", sizeof(struct a));
    return 0;
}

#include<stdio.h>
#include<string.h>
void modify(struct emp*);
struct emp
{
    char name[20];
    int age;
};
int main()
{
    struct emp e = {"Sanjay", 35};
    modify(&e);
    printf("%s %d", e.name, e.age);
    return 0;
}
void modify(struct emp *p)
{
     p ->age=p->age+2;
}

#include<stdio.h>

int main()
{
    struct bits
    {
        int i:40;
    }bit;

    printf("%d\n", sizeof(bit));
    return 0;
}