- void main()
- int number,count=0;
- cout<<"ENTER NUMBER TO CHECK IT IS PRIME OR NOT ";
- for(int a=1;a<=number;a++)
- cout<<" PRIME NUMBER \n";
- cout<<" NOT A PRIME NUMBER \n";
UNDERSTANDING PRIME NUMBERS PROGRAM LOGIC
- To make logic first think about PRIME NUMBER definition that a number which divides by 1 and itself.
- So we have make a condition like that in which user will enter a number and our program will check it by dividing it from 1 up to itself.
- To check that how much times it has divided to numbers from 1 to itself we take a variable and increment it each times when a number is divided.
- In C++ CODING we take a FOR LOOP which will start from 1 up to number that has entered to check whether it is PRIME NUMBER or not with in FOR LOOP we set an IF condition and placed counter (count++) variable in its body so whenever a number from 1 to number which has entered to check divides than IF condition becomes true and counter variable will be incremented.
- When FOR LOOP is completed we check from IF condition that if counter variables value is equal to 2 than number is PRIME else NUMBER IS NOT PRIME.
- Because if number divided two times by 1 and itself counter variable will incremented two times if more than two times counter variable will have value greater than 2.
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Recommended: For fast learning change the logic and do experiment with codes.