DSL_Functions_FamiHug

//Chuong trinh minh hoa danh sach lien ket don - DSL
//by FamiHug@FAMILUG on 16.12.2010
#include <stdio.h>
#include <stdlib.h>

typedef struct hehe{
    int info;
    struct hehe* link;
} dsl;

dsl* Init_DSL(dsl*);
dsl* Insert_Head(dsl*,int);
dsl* Insert_Tail(dsl* l,int x);
dsl* Delete_Head(dsl* l);
dsl* Delete_Tail(dsl* l);
void Print_DSL(dsl*);

int main()
{
    dsl* l=NULL;
    int x,n=-1,i;
    l=Init_DSL(l);

    //Nhap so phan tu
    while(n<0)
    {
        printf("So phan tu cua ds:");
        scanf("%d",&n);
        if(n<0) printf("So phan tu phai lon hon hoac bang 0, nhap lai\n");
    else break;
    }
    //Nhap noi dung cac phan tu theo kieu them dau

    for(i=1;i<=n;i++)
    {
        printf("x%d= ",i);
        scanf("%d",&x);
        l=Insert_Head(l,x);
    }

    //In danh sach
    Print_DSL(l);
    //Them duoi
    printf("Nhap phan tu them vao duoi: ");
    scanf("%d",&x);
    l=Insert_Tail(l,x);
    //IN ds
    Print_DSL(l);
    //Xoa dau
    l=Delete_Head(l);
    l=Delete_Head(l);
    //IN ds
    Print_DSL(l);
    l=Delete_Tail(l);
    Print_DSL(l);
    return 0;
}

dsl * Init_DSL(dsl* l)
{
    return NULL;
}

dsl* Insert_Head(dsl* l,int x)
{
    printf("Them dau: %d",x);
    printf("\n");
    dsl* p=(dsl*)malloc(sizeof(dsl));
    p->info=x;
    if(l==NULL)
    {
        p->link=NULL;
        l=p;
    }
    else
    {
        p->link=l;
        l=p;
    }
    return l;
}
dsl* Insert_Tail(dsl* l,int x)
{
    dsl* t=l;
    dsl* p=(dsl*)malloc(sizeof(dsl));
    p->info=x;
    p->link=NULL;
    printf("Them duoi: %d",x);
    printf("\n");
    if(t==NULL)
    {
        l=p;
    }
    else
    {
        while(t->link!=NULL)
        {
            t=t->link;
        }
        t->link=p;
    }
    return l;
}

//Delete

dsl* Delete_Head(dsl* l)
{
    dsl* t=NULL;
    printf("Xoa dau: ");
    if(l==NULL) printf("Danh sach rong! Khong the xoa dau\n");
    else
    {
        if(l->link==NULL)
        {
            t=l;
            l=NULL;
            free(t);
        }
        else
        {
            t=l;
            l=l->link;
            free(t);
        }
        printf("Da xoa phan tu dau tien cua danh sach!\n");
    }
    return l;
}

dsl* Delete_Tail(dsl* l)
{
    printf("Xoa duoi: ");
    if(l==NULL)
    printf("Danh sach rong! Khong the xoa duoi.\n");
    else
    {
        dsl* t=l;
        if(l->link==NULL)//chi co 1 pt
        {
            t=l;
            l=NULL;
            free(t);
        }
        else
        {
            while(t->link->link!=NULL)
                t=t->link;
            dsl* q=t->link;
            t->link=NULL;
            free(q);
        }
        printf("Da xoa phan tu duoi!\n");
    }
    return l;
}

//Visit
void Print_DSL(dsl* l)
{
    dsl* t=l;
    if(t==NULL) printf("Danh sach: RONG \n");
    else
    {
        printf("Danh sach: ");
        while(t!=NULL)
        {
            printf("%2d",t->info);
            t=t->link;
        }
        printf("\n");
    }
    return;
}