二分查找法

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>



int search(int a[], int n, int num)
{
    int top = 0;
    int bottom = n - 1;
    int half = (top + bottom) / 2;
    while (top <= half)
    {
        printf("这一次查找的数，top=%d,half=%d,bottom=%d\n",top,half,bottom);
        if (a[half] == num)
        {
            return num;//成功找到
        }
        else if (a[half] > num)
        {
            bottom = half - 1;
            half = (top + bottom) / 2;
        }
        else
        {
            top = half + 1;
            half = (top + bottom) / 2;
        }
    }
    return -1;//表示未找到

}

void main()
{
    int num[64];
    time_t tms;
    srand((unsigned int)(time(&tms)));
    for (int i = 0; i < 64; i++)
    {
        num[i] = rand() % 100;
        //printf("%d\n", num[i]);
    }
    for (int i = 0; i < 64 - 1; i++)//为随机生成的数组排序
    {
        for (int j = 0; j < 64 - 1 - i; j++)
        {
            if (num[j]>num[j + 1])
            {
                int tmp = num[j];
                num[j] = num[j + 1];
                num[j + 1] = tmp;
            }
        }
    }
    for (int i = 0; i < 64; i++)//打印出排序后的数组
    {
        printf("%d\n", num[i]);
    }


    int x = 0;
    scanf("%d", &x);
    int result = search(num, 64, x);
    if (result == -1)
    {
        printf("\n未找到%d", x);
    }
    else
    {
        printf("找到了%d", x);
    }
    system("pause");

}