Не работает нормально код

#include <iostream>
using namespace std;
 
int main() {
    const int N = 3;
    int a[N];
    int d = 0;
    int b = 0;
    int c;
 
    for (int i = 0; i < N; i++) {
        cin >> a[N];
        if (a[N] % 2 == 0  && a[N] > d)
            d = a[N];   
        if (a[N] % 2 == 1 && a[N] > b) 
            b = a[N];       
    }
    c = d - b;
    cout << c << endl;
    return 0;
}

#include <iostream>
#include <climits>
using namespace std;
 
int main()
{
    int n, max_even=INT_MIN, max_odd=INT_MIN;
    
    cout << "n="; cin >> n;
 
    int *a = new int[n];
 
    cout << "Enter " << n << " integer numbers:\n";
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
        if (a[i]%2==0 && (max_even==INT_MIN || a[i]>max_even)) max_even=a[i];
        if (a[i]%2 && (max_odd==INT_MIN || a[i]>max_odd)) max_odd=a[i];        
    }
    
    if(max_even!=INT_MIN) cout << "MAX EVEN = " << max_even << "\n";
    else cout << "Even elements are absent\n";
    
    if(max_odd!=INT_MIN) cout << "MAX  ODD = " << max_odd << "\n";
    else cout << "Odd elements are absent\n";
    
    if(max_even!=INT_MIN && max_odd!=INT_MIN)    
        cout << "MAX_EVEN - MAX_ODD = " << max_even-max_odd << "\n";   
 
    delete[]a;
system("pause");
return 0;
}