线性表--算法设计题2.25

假设以两个元素依值递增有序排列的线性表A和B分别表示两个集合（即同一表中的元素值各不相同），现要求另辟空间构成一个线性表C，其元素为A和B中元素的交集，且表C中的元素有依值递增有序排列。试对顺序表编写求C的算法。

 C code：

#include<stdio.h>
#include<stdlib.h>
#define LIST_INIT_SIZE 10
#define LIST_INCREMENT 2
#define ERROR 0
#define OK 1
#define OVERFLOW -1
#define TRUE 1
typedef int Status;

struct SqList
{
     int *elem;
     int length;
     int listsize;
};

void InitList(SqList &L)
{
     L.elem=(int*)malloc(LIST_INIT_SIZE*sizeof(int));
     if(!L.elem)
       exit(OVERFLOW);
     L.length=0;
     L.listsize=LIST_INIT_SIZE;
}

Status ListInsert(SqList &L,int i,int e)
{
     int *newbase,*q,*p;
     if(i<1||i>L.length+1)
       return ERROR;
     if(L.length==L.listsize)
     {
          newbase=(int*)realloc(L.elem,(L.listsize+LIST_INCREMENT)*sizeof(int));
          if(!newbase)
            exit(OVERFLOW);
          L.elem=newbase;
          L.listsize+=LIST_INCREMENT;
         
        }
        q=L.elem+i-1;
        for(p=L.elem+L.length-1; p>=q; --p)
          *(p+1)=*p;
        *q=e;
        ++L.length;
        return OK;
}

void CreateList(SqList &L,int len)
{
     int i,t;
     printf("Please input elems: ");
     for(i=1; i<=len; i++)
     { 
       scanf("%d",&t);
          ListInsert(L,i,t); 
        }
}

void ListTraverse(SqList L,void(*vist)(int&))
{
     int *p=L.elem;
     int i;
     for(i=1; i<=L.length; i++)
     {
          vist(*p++);
        }
        printf("\n");
}

void print1(int &c)
{
     printf("%d ",c);
}

int cmp(const void *a,const void *b)
{
     return *(int*)a - *(int*)b;
}

void ListSort(SqList &L)
{
  qsort(L.elem,L.length,sizeof(int),cmp);    
    
}

void CreateList_C(SqList La,SqList Lb,SqList &Lc)
{
     int i=0,j=0,k=1;
     while(i<La.length && j<Lb.length)
     {
          if(La.elem[i]<Lb.elem[j])
      i++;
    else
    {
         if(La.elem[i]>Lb.elem[j])
           j++;
         else
         {
              ListInsert(Lc,k,La.elem[i]);
              i++;
              k++;
            }
       }         
        }
}

int main()
{
     SqList La,Lb,Lc;
     InitList(La);
     InitList(Lb);
     InitList(Lc);
     int La_len,Lb_len;
     printf("input length of La: ");
     scanf("%d",&La_len);
     printf("input length of Lb: ");
     scanf("%d",&Lb_len);
     CreateList(La,La_len);
     CreateList(Lb,Lb_len); 
     printf("List a: ");
     ListTraverse(La,print1);
     printf("List b: ");
     ListTraverse(Lb,print1);
     printf("After sorting List a: ");
     ListSort(La);
     ListTraverse(La,print1);
     printf("After sorting List b: ");
     ListSort(Lb);
     ListTraverse(Lb,print1);
     CreateList_C(La,Lb,Lc);
     printf("List c: ");
     ListTraverse(Lc,print1);
     return 0;

}