- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
C++ Program to Check Whether a Number can be Expressed as Sum of Two Prime Numbers
The following is an example to check whether a number can be expressed as sum of two prime numbers.
Example
#include <iostream>
using namespace std;
int func(int num) {
int i;
int flag = 1;
for(i = 2; i <= num/2; ++i) {
if(num % i == 0) {
flag = 0;
break;
}
}
return flag;
}
int main() {
int num , i;
cout << "Enter a number : \n";
cin >> num;
for(i = 2; i <= num/2; ++i) {
if (func(i)) {
if (func(num - i)) {
cout << num << " = " << i << " + " << num-i << endl;
}
}
}
return 0;
}Output
Enter a number : 18 18 = 5 + 13 18 = 7 + 11
In the above program, the function func() is checking that the number is prime or not.
int func(int num) {
int i;
int flag = 1;
for(i = 2; i <= num/2; ++i) {
if(num % i == 0) {
flag = 0;
break;
}
}
return flag;
}In the main() function, a number is entered by the user. It is computing the number as sum of two prime numbers.
cout << "Enter a number : \n";
cin >> num;
for(i = 2; i <= num/2; ++i) {
if (func(i)) {
if (func(num - i)) {
cout << num << " = " << i << " + " << num-i << endl;
}
}
}
Updated on 26-Jun-2020 08:38:49
- Related Questions & Answers
- Java Program to Check Whether a Number can be Expressed as Sum of Two Prime Numbers
- Check if a prime number can be expressed as sum of two Prime Numbers in Python
- C program for a number to be expressed as a sum of two prime numbers.
- Check if a number can be expressed as sum two abundant numbers in C++
- Check if a number can be expressed as a sum of consecutive numbers in C++
- Check if an integer can be expressed as a sum of two semi-primes in Python
- Check if a number can be expressed as power in C++
- Check if a number can be expressed as a^b in C++
- Check if a number can be expressed as a^b in Python
- Check if a number can be expressed as 2^x + 2^y in C++
- Program to check a number can be written as a sum of distinct factorial numbers or not in Python
- Check if a number can be represented as a sum of 2 triangular numbers in C++
- C++ program to find ways an integer can be expressed as sum of n-th power of unique natural numbers
- Check if a number can be expressed as x^y (x raised to power y) in C++
- Represent a number as a Sum of Maximum Possible Number of Prime Numbers in C++
Advertisements