Write a C/C++ program that accepts a number from the user and prints “Even” and “Odd”. Your are not allowed to use any comparison (==, <, >..etc) or conditional (if, else, switch, ternary operator,..etc) statement.
Method 1
#include<iostream>
#include<conio.h>
using namespace std;
int main()
{
char arr[2][5] = {"Even", "Odd"};
int no;
cout << "Enter a number: ";
cin >> no;
cout << arr[no%2];
getch();
return 0;
}
Explanation:- Shortest logic ever is arr[no%2] which would return remainder. If remainder become 1, it will print “Odd”. And if remainder become 0, it will print “Even”.
Method 2
#include<stdio.h>
int main()
{
int no;
printf("Enter a no: ");
scanf("%d", &no);
(no & 1 && printf("odd"))|| printf("even");
return 0;
}
Explanation :- Here Most important line is
/* Main Logic */
(no & 1 && printf("odd"))|| printf("even");
//(no & 1) <----------First expression
- Let us understand First expression “no && 1”, if you enter 5 in place of no, your computer will store 5 as in binary like 0000 0000 0000 0101, with this binary you will perform & operation with 0000 0000 0000 0001 (which is 1 in decimal), in result, you get 0000 0000 0000 0001 (which is 1 in decimal), So output of first expression would be 1.
- Output of First expression only become 1 or 0 in every case.
- If output of first expression is 1, then it will perform && operation with printf(“odd”) and it will print ‘odd’.
- If output of first expression is 0, then it will perform && operation with printf(“odd”) which become false because of zero and than || operation is performed with printf(“even”) which will print ‘even’.
