我在使用reverse函数时,没有用#include,为什么编译海口容易通过,程序正常运行??求指教
#include "stdafx.h"
#include<iostream>
//#include<cmath>
#include<vector>
#include<string>
using namespace std;
int flag=1;
int main()
{
int num;
cin>>num;
if(num<0)
cout<<1<<" ";
else
cout<<0<<" ";
num = abs(num);
vector<int> s;
for(int i=0; num !=1; ++i)
{
s.push_back(num%2);
num = num/2;
}
s.push_back(1);
reverse(s.begin(), s.end());
for(vector<int>::iterator it=s.begin(); it!=s.end(); ++it)
cout<<*it<<" ";
}