How to cin to a vector

Question

I\'m trying to ask the user to enter numbers that are put into a vector, then using a function call to count the numbers, why is this not working? I am only able to count t

Answer 1

would be easier if you specify the size of vector by taking an input :

int main()
{
  int input,n;
  vector<int> V;
  cout<<"Enter the number of inputs: ";
  cin>>n;
  cout << "Enter your numbers to be evaluated: " << endl;
  for(int i=0;i<n;i++){
  cin >> input;
  V.push_back(input);
  }
  write_vector(V);
  return 0;
}

Answer 2

You can simply do this with the help of for loop
->Ask on runtime from a user (how many inputs he want to enter) and the treat same like arrays.

int main() {
        int sizz,input;
        std::vector<int> vc1;

        cout<< "How many Numbers you want to enter : ";
        cin >> sizz;
        cout << "Input Data : " << endl;
        for (int i = 0; i < sizz; i++) {//for taking input form the user
            cin >> input;
            vc1.push_back(input);
        }
        cout << "print data of vector : " << endl;
        for (int i = 0; i < sizz; i++) {
            cout << vc1[i] << endl;
        }
     }

Answer 3

These were two methods I tried. Both are fine to use.

int main() {
       
        int size,temp;
        cin>>size;
        vector<int> ar(size);
    //method 1 
      for(auto i=0;i<size;i++)
          {   cin>>temp;
              ar.insert(ar.begin()+i,temp);
          }
          for (auto i:ar) 
            cout <<i<<" "; 
            
     //method 2
     for(int i=0;i<size;i++)
     {
        cin>>ar[i];
     }
     
     for (auto i:ar) 
            cout <<i<<" "; 
        return 0;
    }

Answer 4

#include<iostream>
#include<vector>
#include<sstream>
using namespace std;

int main()
{
    vector<string> v;
    string line,t;
    getline(cin,line);
    istringstream iss(line);
    while(iss>>t)
        v.push_back(t);

    vector<string>::iterator it;
    for(it=v.begin();it!=v.end();it++)
        cout<<*it<<endl;
    return 0;
}

Answer 5

One-liner to read a fixed amount of numbers into a vector (C++11):

#include <algorithm>
#include <iterator>
#include <iostream>
#include <vector>
#include <cstddef>

int main()
{
    const std::size_t LIMIT{5};
    std::vector<int> collection;

    std::generate_n(std::back_inserter(collection), LIMIT,
        []()
        {
            return *(std::istream_iterator<int>(std::cin));
        }
    );

    return 0;
}

Answer 6

You probably want to read in more numbers, not only one. For this, you need a loop

int main()
{
  int input = 0;
  while(input != -1){
    vector<int> V;
    cout << "Enter your numbers to be evaluated: " << endl;
    cin >> input;
    V.push_back(input);
    write_vector(V);
  }
  return 0;
}

Note, with this version, it is not possible to add the number -1 as it is the "end signal". Type numbers as long as you like, it will be aborted when you type -1.