Adding conditions to a conditional statement - c++

Question

I am messing around with dynamic arrays for a user defined amount of inputs for an and gate.
The issue I am running into is that I don't know how many inputs the user is going to test and I need to be able to have an if-else statement that tests each input.
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
class logic_gate {
public:
int x = 0;
};
int main() {
int userInput = 0;
cout << "How many inputs do you want on your and gate?: ";
cin >> userInput;
cout << endl;
logic_gate *and_gate = new logic_gate[userInput];
cout << endl << "Please enter the values of each bit below . . ." << endl <<
endl;
int userTest1 = 0;
for (int i = 0; i < userInput; i++) {
cout << "#" << i + 1 << ": ";
cin >> userTest1;
and_gate[i].x = userTest1;
}
return 0;
}
Here is the code that I am currently trying to find a solution for.

Answer 1

To implement an AND gate with n inputs you can simply do:
int output = 1;
for (int i = 0; i < n; ++i)
{
if (!and_gate [i])
{
output = 0;
break;
}
}
// ...

Answer 2

Use Vector data structure, you don't need to tell its size while declaring, unlike array, and it can grow automatically.
To read input till it's arriving, put cin inside while loop condition. I used getline to read whole line and work with it, so that whenever user presses enter button at empty line, program will think that no more input is coming anymore, and will start calculating 'And' of inputs.
//don't forget to import vector
#include <iostream>
#include <vector>
#include <string>
using namespace std;
class logic_gate {
public:
int x = 0;
logic_gate(){ //default constructor
}
logic_gate(int k){ //another constructor needed
x = k;
}
};
int main(){
cout << endl << "Please enter the values of each bit below . . ." << endl;
vector<logic_gate> and_gate; //no need to tell size while declaration
string b;
while(getline(cin, b)){ //read whole line from standard input
if (b == "\0") //input is NULL
break;
and_gate.push_back(logic_gate(stoi(b))); //to convert string to integer
}
if (!and_gate.empty()){
int output = and_gate[0].x;
for (int i = 1; i < and_gate.size(); i++){
output = output & and_gate[i].x;
}
cout << "And of inputs is: " << output << endl;
}
else{
cout << "No input was given!\n";
}
return 0;
}
Feel free to ask if some doubts linger

Answer 3

I figured out what I wanted to do. Thanks to everyone who helped and especially Paul Sanders. Below is my final code.
#include <iostream>
using namespace std;
class logic_gate {
public:
int x = 0;
};
int main() {
int userInput;
int output = 1;
cout << "How many inputs do you want on your and gate?: ";
cin >> userInput;
cout << endl;
logic_gate *and_gate = new logic_gate[userInput];
cout << endl << "Please enter the values of each bit below . . ." << endl <<
endl;
int userTest1;
for (int i = 0; i < userInput; i++) {
cout << "#" << i + 1 << ": ";
cin >> userTest1;
and_gate[i].x = userTest1;
}
if (userInput == 1) {
output = userTest1;
cout << "The test of " << userTest1 << " is " << output << endl << endl;
}
else if (userInput > 1) {
for (int i = 0; i < userInput; i++) {
if (!and_gate[i].x)
{
output = 0;
break;
}
}
cout << "The test of ";
for (int i = 0; i < userInput; i++) {
cout << and_gate[i].x;
}
cout << " is " << output << endl << endl;
}
return 0;
}