In this tutorial, we will write a C++ program to check for sunny numbers.
What is Sunny Number?
A number N is said to be a sunny number if the number next to the given number (N+1) is a perfect square.
Example: Let us take a Number 8, then the next number is 8+1=9 and as 3 is a square root of 9, hence 8 is a sunny Number.
Another example, let the number be 5, then 5+1=6, that has no square roots, hence 5 is not a sunny Number.
Sunny Number Program in C++
Question: Check if the given number is a sunny number or not in C++ programming.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | #include <iostream> #include <cmath> using namespace std; bool is_sunny(int); //function prototype int main() { int num; cout << "Enter the number: "; cin >> num; if (is_sunny(num)) cout << num << " is a sunny number"; else cout << num << " is NOT a sunny number"; return 0; } bool is_sunny(int n) { // find the square root int square = sqrt(n + 1); return (square *square == n); } |
Output:
Enter the number: 81
81 is a sunny number