5.

#include <iostream>
using namespace std;

int main() {
    int  a = 17, b = -2;
    cоut << a - - b << endl;
    return 0;
}

My guesses

Spoiler

Spoiler

is it easy question? then just choose the unexpected answer :P

Here you can see my set of examples. What do you think about them?

deleted

Spoiler.

One more:

#include <iostream>
using namespace std;

int main() {
	int a = 228, b = 322;
	cout << (a == b) ? 228 : 322;
}

Another one

#include <iostream>
using namespace std;
 
int main() {
    long long a = 1e18 + 1;
    cout << a << endl; 
    return 0;
}

What is the output of the following program?

#include <iostream>

int main()
{
	int a = 0;
	int b = 0;

	// Iterate 3 times
	for (size_t i = 1; i <= 3 || a * b < 10; i++)
	{
		int mult = 9000 * i;

		a += mult;
		b += mult;

		if (a == b)
		{
			std::cout << "Good" << std::endl;
		}
		else
		{
			std::cout << "Bad" << std::endl;
			break;
		}
	}
}

Nice bugs!

Here is one more

#include<bits/stdc++.h>
using namespace std;
void swap(int a,int b)
{
    int t;
    t=a;
    a=b;
    b=t;
}
int main()
{
    int x=5,y=2;
    swap(x,y);
    cout<<x<<" "<<y;
}

After giving all of them a try and referring this:

I still don't get the first one. Why is 020 considered in octal? I didn't get the 3rd one either. Any help?

I did the other 2 correct. Second one was easy (and smart too). For fourth, I suppose that most people assume brackets while reading (They read it something like this : if ((a&b)==0) : although they are careful while writing) and hence must have processed the if part, instead of else! Am I right?

hi please i have a runtime error on test 1 with this code any help???

package graph.party;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
public class Party {
	public static void main(String[] args) {
		
		Scanner in = new Scanner(System.in);
		System.out.println("entrez le nombre des employés\n");
		int n = in.nextInt();
		ArrayList<Integer> tab=new ArrayList<Integer>(n);
		int i=0;
		while(i<n){
       		tab.add(in.nextInt());
       		i++;
		}
		Set<Integer> mySet = new HashSet<Integer>(tab);
		tab.clear();
	tab=new ArrayList<Integer>(mySet);
		System.out.println(tab.size());

	}

}

In 2008, I learned C language by solving these tricky puzzles:

http://www.gowrikumar.com/c/index.php

After so many years, I still don't see a better collection of C language puzzles.

Example from the page:

The following is a piece of C code, whose intention was to print a minus sign 20 times. But you can notice that, it doesn't work.

  #include <stdio.h>
  int main()
  {
      int i;
      int n = 20;
      for( i = 0; i < n; i-- )
          printf("-");
      return 0;
  }

Well fixing the above code is straight-forward. To make the problem interesting, you have to fix the above code, by changing exactly one character. There are three known solutions. See if you can get all those three.