查找（二分查找、顺序查找）

1.针对数组a[8]={-32, 12, 16, 24, 36, 45, 59, 98}，键盘输入一个数实现二分查找。两种方法实现：
（1）所有代码在一个main函数中；

#include<stdio.h>
void main()
{
        int a[8] = { -32, 12, 16, 24, 36, 45, 59, 98 },s, low = 0, high = 7, mid,flag=0;
        scanf("%d", &s);
        while(low<=high) {
               mid = (low + high) / 2;
               if (s > a[mid])
                      low = mid + 1;
               if (s < a[mid])
                      high = mid - 1;
               if (s == a[mid]) {
                      flag = 1;
                      break;
               }
        }
        if (flag == 1)
               printf("找到");
        else
               printf("未找到");
}

（2）一维数组作为函数参数，利用函数调用实现

#include<stdio.h>
int fun(int a[],int s)
{
        int low = 0, high = 7, mid, flag = 0;
        while (low <= high) {
               mid = (low + high) / 2;
               if (s > a[mid])
                      low = mid + 1;
               if (s < a[mid])
                      high = mid - 1;
               if (s == a[mid]) {
                      return flag = 1;
                      break;
               }
        }
}
void main()
{
        int a[8] = { -32, 12, 16, 24, 36, 45, 59, 98 },s,flag=0;
        scanf("%d", &s);
        flag = fun(a, s);
        if (flag == 1)
               printf("找到");
        else
               printf("未找到");
}

2.针对数组a[8] = {32,12,56,78,76,45,43,98}，键盘输入一个数实现顺序查找。两种方法实现：
（1）所有代码在一个main函数中；

#include<stdio.h>
void main()
{
        int a[8] = { 32,12,56,78,76,45,43,98 },s,i;
        scanf("%d", &s);
        for (i = 0; i < 8; ++i) {
               if (a[i] == s) {
                      printf("找到");
                      break;
               }
        }
        if (i == 8)   //在for循环外
               printf("未找到");
}

（2）一维数组作为函数参数，利用函数调用实现

#include<stdio.h>
int fun(int a[], int s)
{
        int i;
        for (i = 0; i < 8; ++i) {
               if (a[i] == s) {
                      return 1;
                      break;
               }
        }
        if (i == 8)
               return 0;
}
void main()
{
        int a[8] = { 32,12,56,78,76,45,43,98 },s,i,flag;
        scanf("%d", &s);
        flag = fun(a, s);
        if(flag==1)
               printf("找到");
        else
               printf("未找到");     
}