Write a c program to perform shanon coding.

//Write a c program to perform shanon coding.

#include<stdio.h>

#include<conio.h>

#include<string.h>

struct node

{

            charsym[10];

            float pro;

            intarr[20];

            int top;

}s[20];

typedefstruct node node;

void prints(intl,inth,node s[])

{

            int i;

            for(i=l;i<=h;i++)

            {

                        printf("\n%s%f",s[i].sym,s[i].pro);

            }

}

voidshannon(intl,inth,node s[])

{

            float pack1=0,pack2=0,diff1=0,diff2=0;

            inti,d,k,j;

            if((l+1)==h || l==h || l>h)

            {

                        if(l==h || l>h)

                        return;

                        s[h].arr[++(s[h].top)]=0;

                        s[l].arr[++(s[l].top)]=1;

                        return;

            }

            else

            {

                        for(i=l;i<=h-1;i++)

                        pack1=pack1+s[i].pro;

                        pack2=pack2+s[h].pro;

                        diff1=pack1-pack2;

                        if(diff1< 0)

                        diff1=diff1*-1;

                        j=2;

                        while(j!=h-l+1)

                        {

                                    k=h-j;

                                    pack1=pack2=0;

                                    for(i=l;i<=k;i++)

                                                pack1=pack1+s[i].pro;

                                    for(i=h;i>k;i--)

                                                pack2=pack2+s[i].pro;

                                                diff2=pack1-pack2;

                                                if(diff2< 0)

                                                            diff2=diff2*-1;

                                                            if(diff2>=diff1)

                                                            break;

                                                            diff1=diff2;

                                                            j++;

                        }

                        k++;

                        for(i=l;i<=k;i++)

                                    s[i].arr[++(s[i].top)]=1;

                                    for(i=k+1;i<=h;i++)

                                                s[i].arr[++(s[i].top)]=0;

                                                shannon(l,k,s);

                                                shannon(k+1,h,s);

            }

}

void main()

{

            intn,i,j;

            floatx,total=0;

            charch[10];

            node temp;

            clrscr();

            printf("Enter How Many Symbols Do You Want To Enter: ");

            scanf("%d",&n);

            for(i=0;i<n;i++)

            {

                        printf("Enter symbol %d--> ",i+1);

                        scanf("%s",ch);

                        strcpy(s[i].sym,ch);

            }

            for(i=0;i<n;i++)

            {

                        printf("\nEnter probability for %s--> ",s[i].sym);

                        scanf("%f",&x);

                        s[i].pro=x;

                        total=total+s[i].pro;

                        if(total>1)

                        {

                                    printf("\tThis probability is not possible.Enter new probability");

                                    total=total-s[i].pro;

                                    i--;

                        }

            }

            s[i].pro=1-total;

            for(j=1;j<=n-1;j++)

            {

                        for(i=0;i< n-1;i++)

                        {

                                    if((s[i].pro)>(s[i+1].pro))

                                    {

                                                temp.pro=s[i].pro;

                                                strcpy(temp.sym,s[i].sym);

                                                s[i].pro=s[i+1].pro;

                                                strcpy(s[i].sym,s[i+1].sym);

                                                s[i+1].pro=temp.pro;

                                                strcpy(s[i+1].sym,temp.sym);

                                    }

                        }

            }

            for(i=0;i<n;i++)

                        s[i].top=-1;

                        shannon(0,n-1,s);

                        printf("---------------------------------------------------------------");

                        printf("\n\n\n\tSymbol\tProbability\tCode");

                        for(i=n-1;i>=0;i--)

                        {

                                    printf("\n\t%s\t%f\t",s[i].sym,s[i].pro);

                                    for(j=0;j<=s[i].top;j++)

                                                printf("%d",s[i].arr[j]);

                        }

                        printf("\n---------------------------------------------------------------");

                        getch();

}