Given an odd number N, the task is to find if the number can be represented as the sum of 3 prime numbers.
Examples:
Input: N = 7 Output: Yes Explanation: 2 + 2 + 3 = 7 Input: N = 17 Output: Yes Explanation: 2 + 2 + 13 = 17
Approach:
In number theory, Goldbach’s weak conjecture, also known as the odd Goldbach conjecture, the ternary Goldbach problem, or the 3-primes problem, states that Every odd number greater than 5 can be expressed as the sum of three primes. (A prime may be used more than once in the same sum.).
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // if a number can // be represent as // as a sum of 3 prime void check( int n) { if (n % 2 == 1 && n > 5) cout << "Yes\n" ; else cout << "No\n" ; } // Driver code int main() { int a = 3; int b = 7; check(a); check(b); return 0; } // This code is contributed by 29AjayKumar |
Java
class GFG { // Function to check // if a number can // be represent as // as a sum of 3 prime static void check( int n) { if (n % 2 == 1 && n > 5 ) { System.out.println( "YES" ); } else { System.out.println( "NO" ); } } // Driver code public static void main(String[] args) { int a = 3 ; int b = 7 ; check(a); check(b); } } // This code is contributed by PrinciRaj1992 |
Python3
# Function to check # if a number can # be represent as # as a sum of 3 prime def check(n): if n % 2 = = 1 and n > 5 : print ( 'YES' ) else : print ( 'NO' ) # Driver code def main(): a = 3 b = 7 check(a) check(b) main() |
C#
using System; class GFG { // Function to check // if a number can // be represent as // as a sum of 3 prime static void check( int n) { if (n % 2 == 1 && n > 5) { Console.Write( "YES" ); } else { Console.WriteLine( "NO" ); } } // Driver code public static void Main(String[] args) { int a = 3; int b = 7; check(a); check(b); } } // This code is contributed by PrinciRaj1992 |
Javascript
// Function to check // if a number can // be represent as // as a sum of 3 prime function check(n) { if (n % 2 == 1 && n > 5) { document.write( "YES" ); } else { document.write( "NO" + "<br>" ); } } // Driver code var a = 3; var b = 7; check(a); check(b); // This code is contributed by shivanisinghss2110 |
NO YES
Time Complexity: O(1)
Auxiliary Space: O(1)
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