問題及程式碼：

#include <stdio.h>  
#define MAXL 100  
typedef int KeyType;  
typedef char InforType[10];  
typedef struct  
{  
KeyType key;  
InforType data;  
}NodeType;  
typedef NodeType SeqList[MAXL];  
int BinSearch(SeqList R,int n,KeyType k)  
{  
int low=0,high=n-1,mid;  
 while(low<=high)  
 {  
  mid=(high+low)/2;  
  if(R[mid].key==k)  
      return mid+1;  
  if(R[mid].key>k)  
      high=mid-1;  
  else  
      low=mid+1;  
 }  
 return 0;  
}  
int main()  
{  
    int i,n=10;  
    int result;  
    SeqList R;  
    KeyType a[]= {12,18,24,35,47,50,62,83,90,115,134},x;  
    for (i=0; i<n; i++)  
        R[i].key=a[i];  
    result = BinSearch(R,n,x);  
    x=90;  
    if(result>0)  
        printf("序列中第 %d 個是 %d\n",result, x);  
    else  
        printf("木有找到！\n");  
    result = BinSearch(R,n,x);  
    x=47;  
    if(result>0)  
        printf("序列中第 %d 個是 %d\n",result, x);  
    else  
        printf("木有找到！\n");  
    result = BinSearch(R,n,x);  
  
    x=100;  
    if(result>0)  
        printf("序列中第 %d 個是 %d\n",result, x);  
    else  
        printf("木有找到！\n");  
    result = BinSearch(R,n,x);  
  
  
    return 0;  
}