c语言编程实现“折半查找”的过程。

//参考代码如下：

#include <stdio.h>

int main()

{

int i, j, n, k=0, isFound=0

int num[15] = {88,86,75,74,61,56,52,43,39,34,31,22,18,16,8} //测试数组

printf("请输出一个整数：\n")

scanf("%d", &n)

i = (int)15/2 //对折位移量

j = (int)15/2 //取数“指针”

while(k<游缺2)

{

i = (int)i/2

if(i == 0) k++//i==0 即折半到无可再折时，仍有最后一察陆次比较，故以k做计数

//若未相等，计算下一循环指针的位置

if(n<num[j])

j = j + (i + 1)

else if(n>num[j])

j = j - (i + 1)

else

{

isFound = 1

break //若败磨顷找到相等数，标记已找到并退出循环

}

}

//输出结果

if(isFound)

printf("该数是数组中第%d个元素的值\n", j)

else

printf("查无此数！\n")

return 0

}

#include\x0d\x0a\x0d\x0a#define N 20\x0d\x0a\x0d\x0aint Binary(int a[], int n, int found)\x0d\x0a{\x0d\x0aint low = 0\x0d\x0aint high = n - 1\x0d\x0aint mid\x0d\x0ado\x0d\x0a{\x0d\x0amid = (low + high) / 2\x0d\x0aif(found == a[mid])\x0d\x0areturn mid\x0d\x0aelse if(found high = mid - 1\x0d\x0aelse\x0d\x0alow = mid + 1\x0d\x0a}while(low return -1\x0d\x0a}\x0d\x0a\x0d\x0avoid main()\x0d\x0a{\x0d\x0aint found,a[N] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}\x0d\x0aprintf("please input a number\n")\x0d\x0ascanf("%d",&found)\x0d\x0aif(Binary(a,N, found))\x0d\x0aprintf("在数悄返组中基灶的位置是 %d\n",Binary(a,N, found))\x0d\x0aelse\x0d\x0aprintf("没有找启锋饥到\n")\x0d\x0a}

#include<stdio.h>

int main()

{int a[16]={15,14,13,12,11,10,9,8,7,6,5,4,3,1,0}

 int l=0,r=15,mid,x

 scanf("%d",&x)

 do

 {mid=(l+r)/2

  if(a[mid]==x)break

  if(x>a[mid])r=mid-1

    else l=mid+1

 }while(l<=r)

 if(a[mid]==x)

  坦烂 printf("a[%d]=%d\n",mid,x)

 else

 知局  printf("无此数\n")  

 return 让猛漏0    

}

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