how to solve this using Arrays? - c++

Question

I'm new to programming is there a way to solve this:
Take 10 integer inputs from user and print the following
number of positive numbers.
number of negative numbers.
number of odd numbers.
number of even numbers
#include <iostream>
using namespace std;
int main()
{
int numArray[10];
cout<<"Enter Number :";
for(int i=0; i<10; i++)
{
cin>>numArray[i];
}
for(int i=0; i<numArray[i]; i++)
{
if(numArray[i]>0)
{
cout<<"Positive Number "<<numArray[i] <<endl;
}
else
{
cout<<"Negative Number "<<numArray[i]<<endl;
}
if(numArray[i]%2==0)
{
cout<<"Odd number "<<numArray[i]<<endl;
}
else
{
cout<<"even number "<<numArray[i]<<endl;
}
}
return 0;
}

Answer 1

You could do this without arrays but I'm just gonna stick with your original intent for clarity.
#include <iostream>
#include <array>
using namespace std;
int main()
{
array<int, 10> numArray; //an array of ints, size 10. this is CPP style array, it is 'safer' than C-style array. (someone correct me)
//get your 10 inputs.
cout << "Enter Number :";
for(size_t i = 0; i < numArray.size(); i++)
{
cin >> numArray[i];
}
int positive_count = 0;
int negative_count = 0;
int even_count = 0;
int odd_count = 0;
//loop thru your 10 inputs, increment counters accordingly.
for(size_t i = 0; i < numArray.size(); i++)
{
if (numArray[i] < 0)
{
negative_count += 1;
}
if (numArray[i] > 0)
{
positive_count += 1;
}
if (numArray[i] % 2 == 0)
{
even_count += 1;
}
else
{
odd_count += 1;
}
}
cout << "Positive Number " << positive_count << endl;
cout << "Negative Number " << negative_count << endl;
cout << "even number " << even_count << endl;
cout << "Odd number " << odd_count << endl;
return 0;
}

Answer 2

You could do it in input loop:
int positives = 0, zeros = 0, odds = 0;
int negatives = 0, evens = 0;
for(size_t i = 0; i < numArray.size(); i++)
{
cin >> numArray[i];
// increment number of odds
odds += numArray[i] & 0x1;
// odds += numArray[i] % 2;
// increment number of positives
positives += (numArray[i] > 0);
// positives += (numArray[i] > 0 ? 1 : 0);
// increment zeros
zeros += !(numArray[i] | 0);
}
evens = 10 - odds;
negatives = 10 - zeros - positives;
cout << "Positive count " << positives << endl;
cout << "Negative Number " << negatives << endl;
cout << "Even number " << evens << endl;
cout << "Odd number " << odds << endl;
and here is newbie friendly version:
int positives = 0, zeros = 0, odds = 0;
int negatives = 0, evens = 0;
for(size_t i = 0; i < numArray.size(); i++)
{
cin >> numArray[i];
// increment number of odds
if (numArray[i] % 2 == 1)
odds++;
if (numArra[i] == 0)
zeros++;
else if (numArray[i] > 0)
positives++;
}
evens = 10 - odds;
negatives = 10 - zeros - positives;
cout << "Positives " << positives << '\n';
cout << "Negatives " << negatives << '\n';
cout << "Evens " << evens << '\n';
cout << "Odds " << odds << '\n';