A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. It means a prime number is only divisible by 1 and itself, and it start from 2. The smallest prime number is 2.
Example
#include<iostream.h> #include<conio.h> void main() { int i,no; clrscr(); cout<<"Enter any num: "; cin>>no; if(no==1) { cout<<"Smallest prime num is 2"; } for(i=2;i<no;i++) { if(no%i==0) { cout<<"Not prime num"; break; } } if(no==i) { cout<<"Prime num"; } getch(); }
Output
Enter any num: 10 Not Prime Num
Print next Prime number
When we enter any number this code will print next Prime number.
Example: Suppose we enter 5 then next prime number is 7.
Example: Suppose we enter 5 then next prime number is 7.
Example
#include<iostream.h> #include<conio.h> void main() { int i,j=2,num; clrscr(); cout<<"Enter any num: "; cin>>num; cout<<"Next prime num: "; for(i=num+1;i<3000;i++) { for(j=2;j<i;j++) { if(i %j==0) { break; } // if } // for if(i==j || i==1) { cout<<"\t"<<i; break; } // if } // outer for getch(); }
Output
Enter any num: 10 Next prime num 11
