程序代码：

#include <stdio.h>
#define maxsize 100
typedef struct seqlist
{
    int data[maxsize];
    int len;
};
//顺序查找非递归
int seqsearch(seqlist l,int key)
{
    int k=l.len-1;
    while(k>=0&&l.data[k]!=key)
        k--;
    return k;
}
int seqsearch(seqlist l,int n,int key)
{
    int k=0;
    if(-1==n)
        k=-1;
    else
        if(l.data[n]==key)
            k=n;
        else
            k=seqsearch(l,n-1,key);
    return k;
}

void main()
{
    int i,k;
    int  key;
    seqlist l;
    printf(" please input the  length of list:");
    scanf("%d",&l.len);
    printf("please input the data of list:\n");
    for (i=0;i<l.len;i++)
        scanf("%d",&l.data[i]);
    do
    {
        printf("请输入待查找的关键字（-1 退出）：");
        scanf("%d",&key);
        if(key==-1) break;
        if((k=seqsearch(l,l.len,key)!=-1))
            printf("%d 在线性表的第%d个位置。\n",key,k);
        else
            printf("未找到指定元素！\n");
    }
    while(key!=-1);
}