C语言实现如下：
[cpp]
#include
void display(int array[],int size){
printf("the array is:");
int i;
for(i=0;i
printf("%d ",array[i]);
}
printf("\n");
}
void middle(int array[],int size,int num){
int first=0,last=size-1,middle=0;
while(first <= last){
middle = (first+last)/2;
if(array[middle] > num){
last = middle-1;
}else if(array[middle] < num){
first = middle+1;
}else{
printf("this num index is %d\n",middle);
return;
}
}
printf("this num is not found\n");
}
int main(void){
int array[10]={1,2,46,67,69,120,121,262,456,500};
display(array,10);
middle(array,10,121);
return 0;
}