bits.c

#include<stdio.h>
#include<stdlib.h>
#define SIZE(n) (n+8-(n%8))/8
#define PRESENT 1
#define ABSENT 0
#define POS(n) n/8
struct number
{
    unsigned char num0:1;
    unsigned char num1:1;
    unsigned char num2:1;
    unsigned char num3:1;
    unsigned char num4:1;
    unsigned char num5:1;
    unsigned char num6:1;
    unsigned char num7:1;
};
void set(int num,struct number list[]);
void display(int limit,struct number list[]);
void SetToZero(int limit,struct number list[]);
main()
{
    int num=0,upper;
    printf("\nEnter largest number in list ");
    scanf("%d",&upper);
    upper+=1;
    struct number list[SIZE(upper)];
    printf("%d",sizeof list);
    SetToZero(SIZE(upper),list);
    printf("Enter the list  ");
    scanf("%d",&num);
    while(num<upper)
    {
        set(num,list);
        scanf("%d",&num);
    }
    display(SIZE(upper),list);
}
void SetToZero(int limit,struct number list[])
{
//Initialized the whole list with 0
    int i;
    for(i=0;i<limit;i++)
    {
        list[i].num0=ABSENT;
        list[i].num1=ABSENT;
        list[i].num2=ABSENT;
        list[i].num3=ABSENT;
        list[i].num4=ABSENT;
        list[i].num5=ABSENT;
        list[i].num6=ABSENT;
        list[i].num7=ABSENT;
    }
}
void set(int num,struct number list[])
{
//Function sets the recieved number on to the list
    switch(num%8)
    {
        case 0:
            list[POS(num)].num0=PRESENT;
            break;
        case 1:
            list[POS(num)].num1=PRESENT;
            break;
        case 2:
            list[POS(num)].num2=PRESENT;
            break;
        case 3:
            list[POS(num)].num3=PRESENT;
            break;
        case 4:
            list[POS(num)].num4=PRESENT;
            break;
        case 5:
            list[POS(num)].num5=PRESENT;
            break;
        case 6:
            list[POS(num)].num6=PRESENT;
            break;
        case 7:
            list[POS(num)].num7=PRESENT;
            break;
    }
}
void display(int limit,struct number list[])
{
//Displays the list,automatically sorted
    int i=0;
    for(i=0;i<limit;i++)
    {
        if(list[i].num0)
            printf("%d\t",i*8);
        if(list[i].num1)
            printf("%d\t",i*8+1);
        if(list[i].num2)
            printf("%d\t",i*8+2);
        if(list[i].num3)
            printf("%d\t",i*8+3);
        if(list[i].num4)
            printf("%d\t",i*8+4);
        if(list[i].num5)
            printf("%d\t",i*8+5);
        if(list[i].num6)
            printf("%d\t",i*8+6);
        if(list[i].num7)
            printf("%d\t",i*8+7);
    }
    printf("\n");
}