The signed right shift operator '>>' uses the sign bit to fill the trailing positions. For example, if the number is positive then 0 will be used to fill the trailing positions and if the number is negative then 1 will be used to fill the trailing positions.

Hence we can say that if a number is positive and we right shift it by 31, then we will get zero, and if the number is negative then we will get -1.

Approach:

Right Shift n by 31.
If we get 0 then n is positive.
If we get -1 then n is negative.

Code

#include <bits/stdc++.h>
using namespace std;

// Function to check if a number is positive or negative using bitwise shift
void check(int n) {
    // If the most significant bit (31st bit) is 0, the number is positive
    if (n >> 31 == 0) {
        cout << n << " is positive." << endl;
    } 
    // If the most significant bit (31st bit) is 1, the number is negative
    else {
        cout << n << " is negative." << endl;
    }
}

int main() {
    // Example 1: Check if the number is positive or negative
    int n = 5;
    check(n);  // Output: 5 is positive.

    // Example 2: Check if the number is positive or negative
    n = -6;
    check(n);  // Output: -6 is negative.

    return 0;
}

                            