Write a program in C++ to Check Whether a Number can be Express as Sum of Two Prime Numbers using the friend function.
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#include<iostream> using namespace std; class T4Tutorials { protected : int n, i, num1,num2,num3,j; public : int checK() { num1=1,num2=1,num3=0; cout<<"Input a positive integer: "; cin>>n; } friend int show(T4Tutorials); }; int show(T4Tutorials a) { for(a.i=3; a.i<=a.n/2; a.i++) { /* prime no?*/ a.num1=1; a.num2=1; for(a.j=2; a.j<a.i; a.j++) { if(a.i%a.j==0) { a.num1=0;a.j=a.i;} } for(a.j=2; a.j<a.n-a.i; a.j++) { if((a.n-a.i)%a.j==0) { a.num2=0;a.j=a.n-a.i;} } if(a.num1==1 && a.num2==1) { printf("%d = %d + %d \n",a.n,a.i,a.n-a.i); a.num3=1;} } if(a.num3==0) { cout<<a.n<<"can not be expressed as sum of two prime numbers.\n\n"; } } int main() { T4Tutorials a; a.checK(); show(a); } |