Câu 3

#include<iostream>
using namespace std;
void input(int a[100],int n)
{
    cout<<"input: "<<endl;
    for (int i=0;i<n;i++)
    {
        cout<<"a["<<i<<"]= ";
        cin>>a[i];
    }
    cout<<"output: ";
    for (int i=0; i<n; i++)
    {
        cout<<a[i]<<" ";
    }
}
void HoanDoi(int &a, int &b)
{
    a=a+b;
    b=a-b;
    a=a-b;
}
int main()
{
    int n, a[100];
    int max1=0, max2=0, max3=0;
    cout<<"Nhap so phan tu: ";
    cin>>n;
    input(a,n);
    for (int i=0; i<n;i++)
    {
        if (max1 < a[i])
        {
            int temp=max1;
            max1=a[i];
            if (temp>max2)
            {
                HoanDoi(temp,max2);
            }
            if (temp>max3)
            {
                max3=temp;
            }
        }
        else if (max2<a[i] && a[i]!=max1)
        {
            int temp=max2;
            max2=a[i];
            if (temp>max3)
            {
                max3=temp;
            }
        }
        else if (max3<a[i] && a[i]!= max1 && a[i]!=max2)
        {
            max3=a[i];
        }
    }
    cout<<endl;
    cout<<"3 so lon nhat: "<<max1<<" "<<max2<<" "<<max3<<endl;
    system("pause");
    return 0;
}