#include <iostream>
#include <conio.h>

using namespace std;

int main(){

setlocale(LC_ALL, "Russian");

cout << "Введите три числа: ";
int a[2];
cin >> a[0]; cin >> a[1]; cin >> a[2];

if (a[0] < a[1] && a[0] < a[2])
 a[0] = 0;

else if (a[1] < a[0] && a[1] < a[2])
 a[1] = 0;

else if (a[2] < a[1] && a[2] < a[0])
 a[2] = 0;

cout << endl;
cout << a[0] << " " << a[1] << " " << a[2];

_getch();
return 0;
}

//Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x64

#include <iostream>
#include <algorithm>
#include <array>
using namespace std;

int main()
{
    array<int, 3> arr = { 5, -3, 9 };
    replace(arr.begin(), arr.end(), *min_element(arr.cbegin(), arr.cend()), 0);
    copy(arr.cbegin(), arr.cend(), ostream_iterator<int>(std::cout, " "));
}