输入一个数，查找它在数组中的下标

输入一个数，查找它在数组中的下标

#include "stdafx.h"
#include<iostream>
using namespace std;
#define ERROR 1
#define LONGERROR -1
#define POINTERROR -2
int Find(int ar[],int p,int n )
{
	if (p == NULL)return POINTERROR;
	if (n < 1)return LONGERROR;
	for (int i = 0; i < n; i++)
	{
		if (p == ar[i]){ return i + 1;  }
	}  
	return ERROR;
}
int main()
{
	char ch;
	
	int a, b, ar[] = {12,23,34,45,56,67,78,89,90,100 };
	int n = sizeof(ar) / sizeof(ar[0]);
	for (;;)
	{
		cout << "输出要查找的数：";
		cin >> a;
		b = Find(ar, a, n);
		switch (b)
		{
		case POINTERROR:cout << "输入的数据为空" << endl << endl; break;
		case LONGERROR: cout<< "此数组为空" << endl << endl; break;
		case ERROR:cout << "此数组中没有这个数" << endl << endl; break;
		default:cout << "他是第" << b  << "个数" << endl<<endl; break;
		}
		cout << "继续查找输入Y，退出输入N" << endl << endl;
		cin >> ch;
		if (ch == 'N' || ch == 'n')break;
	}
	return 0;
}

输出结果：