二進制搜索/查找程序(C語言)，如下代碼所示：

#include <stdio.h>

#define MAX 20

// array of items on which linear search will be conducted.
int intArray[MAX] = {1,2,3,4,6,7,9,11,12,14,15,16,17,19,33,34,43,45,55,66};

void printline(int count){
int i;
for(i = 0;i <count-1;i++){
printf("=");
}
printf("=\n");
}

int find(int data){
int lowerBound = 0;
int upperBound = MAX -1;
int midPoint = -1;
int comparisons = 0;
int index = -1;

while(lowerBound <= upperBound){
printf("Comparison %d\n" , (comparisons +1) ) ;
printf("lowerBound : %d, intArray[%d] = %d\n", lowerBound,lowerBound,intArray[lowerBound]);
printf("upperBound : %d, intArray[%d] = %d\n", upperBound,upperBound,intArray[upperBound]);
comparisons++;

  // compute the mid point 
  midPoint = (lowerBound + upperBound) / 2;

  // data found
  if(intArray\[midPoint\] == data){
     index = midPoint;
     break;
  }
  else {
     // if data is larger 
     if(intArray\[midPoint\] < data){
        // data is in upper half
        lowerBound = midPoint + 1;
     }
     // data is smaller 
     else{           
        // data is in lower half 
        upperBound = midPoint -1;
     }
  }               

}
printf("Total comparisons made: %d" , comparisons);
return index;
}

void display(){
int i;
printf("[");

// navigate through all items
for(i = 0;i<MAX;i++){
printf("%d ",intArray[i]);
}

printf("]\n");
}

main(){
printf("Input Array: ");
display();
printline(50);

//find location of 1
int location = find(55);

// if element was found
if(location != -1)
printf("\nElement found at location: %d" ,(location+1));
else
printf("\nElement not found.");
}

如果我們編譯並運行上述程序，那麼這將產生以下結果 -

Input Array: [1 2 3 4 6 7 9 11 12 14 15 16 17 19 33 34 43 45 55 66 ]

Comparison 1
lowerBound : 0, intArray[0] = 1
upperBound : 19, intArray[19] = 66
Comparison 2
lowerBound : 10, intArray[10] = 15
upperBound : 19, intArray[19] = 66
Comparison 3
lowerBound : 15, intArray[15] = 34
upperBound : 19, intArray[19] = 66
Comparison 4
lowerBound : 18, intArray[18] = 55
upperBound : 19, intArray[19] = 66
Total comparisons made: 4
Element found at location: 19