技術標籤：C語言程式設計c語言演算法

【題目】C語言採用折半查詢法在10個有序數中尋找某個數，如果找到，輸出其所在陣列中下標的位置，否則，輸出沒找到。

【原始碼】

#include <stdio.h>
int main(void)
{
    int  up=10, low=1, mid, found=0, find;
    int  a[10]= {1, 5, 6, 9, 11, 17, 25, 34, 38, 41};
    scanf("%d", &find);
    printf("\n");
    while (up >=
 
 low  ||  !found)
    {
        mid = (up + low) / 2;
        if(a[mid] == find)
        {
            found = 1;
            break;
        }
        else  if(a[mid] > find)
        {
            if(a[mid] > find && a[mid+1] < find)
            {
                found = 0;
                break
 
;
            }
            up = mid - 1;
        }
        else
        {
            if(a[mid] < find && a[mid + 1] > find)
            {
                found = 0;
                break;
            }
            low = mid + 1;
        }
        if(mid <=0 || mid >= 9)
        {
 

            found = 0;
            break;
        }
    }
    if(found)
        printf("found number is %dth.\n", mid);
    else
        printf("no  found.\n");
	return 0;
}

【執行結果】