md已经开了40个窗口了，error此起彼伏555

#include<bits/stdc++.h>
#include<conio.h>
#include<unistd.h>
#include<stdlib.h>
#include <stddef.h>

using namespace std;
int target;
vector<int>nums;
vector<int>::iterator it;
void sorting(){
	sort(nums.front(),nums.back(),nums.size());
}

bool state;

void Main(){
	extern int a;
	bool state=true;
		if(nums.empty()==true)
			while(state==true)
				cin>>a;
				if(typeof(a) ==int ){
					state=false;
					for(int i=0;i<=nums.size();i++)
						{
							nums.push_back(a);
					 	 }	   
					}
				else
				{	 printf("typeof input is not right!");
					 sleep(1);
					 system("clscr");
					 
					 state=true;
				 } 
	sorting();	
}

说是typeof缺少标识符？？？