折半查找&clock函数

#include <stdio.h>
#include <time.h>

#define CLOCKS_PER_SEC ((clock_t)1000)

int binsearch(int, int array[], int n);

int main()
{

  int array[] = {2, 5, 6, 8, 9, 11, 12, 13, 14, 15, 16};
  int tag = 9;
  int res = -1;

  clock_t start;
  clock_t finish;

  start = clock();
  res = binsearch(9, array, 11);
  finish = clock();

  printf("%ld %ld ", start, finish);
  printf("%d %f ", res, (double)(finish-start)/CLOCKS_PER_SEC);

  return 0;
}


int binsearch(int tag, int array[], int n)//对顺序数组,进行折半查找
{
  int low = 0;
  int high = n-1;
  int mid = 0;

  long i = 4500000;
  while(i--);

  while(low <= high)
  {
    mid = (low+high)/2;

    if(tag > array[mid])
    {
      low = mid + 1;
    }
    else if(tag < array[mid])
    {
      high = mid - 1;
    }
    else
    {
      return mid;
    }

  }

  return -1;

}

原文地址:https://www.cnblogs.com/zhangxuan/p/5942252.html