bisearch.cpp

数据结构c++-书的一些源代码

#include <iostream.h>
#include "datatype.h"

int BiSeach(datatype a[], int n, keytype key)
//在有序表a[0]--a[n-1]中二分查找关键码为key的对象
//查找成功时返回该对象的下标序号；失败时返回-1
{
   int low = 0, high = n - 1, mid;

   while(low <= high)
   {
      mid = (low + high)/2;
      if(a[mid].key == key) return mid;
      else if(a[mid].key < key) low = mid + 1;
      else high = mid - 1;
   }

   return -1;
}

void main(void)
{
	datatype Test[] = {2,3,5,7,9,11,13,15,17,20};
	int n = 10, key = 11, i;

	if((i = BiSeach(Test, n, key)) != -1)
		cout << "查找成功! 该对象为第" << i << "个对象";
	else  cout << "查找失败! 该对象在对象集合中不存在";
}