int n = 10;
int a[n];
for (int i = 0; i < n; i++)
{
cin >> a[i];
}
This is how I input array when we know the size of n. But when we don't know the size of n and we have to take input in an array and stop taking inputs when there is a new line. How can we do that in C++?
std::vector<int> is what you need. Think of it as an array of dynamic size.
you can add elements to a vector by using .push_back()
To stop taking input you need to use EOF Concept. i.e. End of File. Place the cin in a while loop. Something like this -
while (cin >> n)
{
a.push_back(n);
}
You will probably need a vector of type string unless you are using stoi();
So basically something like the code below.
int n = 10;
vector<string> a;
string temp;
while(cin>>temp)
{
a.push_back(temp);
}
or
vector<int> a;
while(cin>>temp)
{
a.push_back(stoi(temp));
}
So this prevents you from doing error checking, but at least for my toy projects is to use vector with an istream_iterator So something like this:
const vector<int> a{ istream_iterator<int>{ cin }, istream_iterator<int>{} }
std::vectorrather than a fixed-size array.std::vector.