构造顺序表--合并两个按元素从小到大排列的顺序表

/*******************************顺序表***************************/

#include<stdio.h>

#include<stdlib.h>//malloc,realloc,exit

#define TRUE 1

#define FALSE 0

#define OK 1

#define ERROR 0

#define INFEASIBLE -1

#define OVERFLOW -2

#define LIST_INIT_SIZE 100

#define LISTINCREMENT 10

typedef int Status;

typedef int ElemType;

typedef struct{         //结构

 ElemType *elem;     //L.elem[i]表示第i+1个位置的元素的值，等价于*(L.elem+i)

 int length;

 int listsize;

}SqList;

Status InitList_Sq(SqList &L){              //初始化

    L.elem=(ElemType *)malloc(LIST_INIT_SIZE*sizeof(ElemType));//malloc

 L.length=0;

 L.listsize=LIST_INIT_SIZE;

 return OK;

}

Status ListInsert_Sq(SqList &L,int i,ElemType e){               //插入元素

 ElemType *newbase,*q,*p;

 if(i<1||i>L.length+1) return ERROR;

 if(L.length>=L.listsize)

 {

        newbase=(ElemType *)realloc(L.elem,(L.listsize+LISTINCREMENT)*sizeof(ElemType));//realloc

     if(!newbase) exit(OVERFLOW);

   L.elem=newbase;

  L.listsize+=LISTINCREMENT;

 }

    q=&(L.elem[i-1]);//

 for(p=&(L.elem[L.length-1]);p>=q;--p) *(p+1)=*p;

 *q=e;

 ++L.length;

 return OK;

}

Status ListDelete_Sq(SqList &L,int i,ElemType &e)//删除元素   //实参前加&，主函数中值被修改，相当于实参是指针

{

 ElemType *p,*q;

 q=L.elem +L.length-1;

 e=L.elem[i-1];

 for(p=L.elem+i;p<=q;p++)

 {

        *(p-1)=*p;

 }

 L.length--;

 return OK;

}

void MergeList(SqList La,SqList Lb,SqList &Lc)//把两个按元素从小到大排列的顺序表合并

{

    ElemType *pa,*pb,*pc,*pa_last,*pb_last;

 pa=La.elem;

 pb=Lb.elem;

 Lc.length=0;

 Lc.listsize=La.length+Lb.length;

    pc=Lc.elem=(ElemType*)malloc(Lc.listsize*sizeof(ElemType));

 if(!Lc.elem) exit(OVERFLOW);

    pa_last=La.elem+La.length-1;

    pb_last=Lb.elem+Lb.length-1;

 while(pa<=pa_last&&pb<=pb_last)

 {

        if(*pa<*pb) *pc++=*pa++;//*pc=*pa; pa++; pc++;

  else if(*pa=*pb) {*pc++=*pa++; pb++; }

  else *pc++=*pb++;

  Lc.length++;

 }

 while(pa<=pa_last) {*pc++=*pa++; Lc.length++;}

 while(pb<=pb_last) {*pc++=*pb++; Lc.length++;}

}