Aim:
Write a program to find the sum of all primes below two million.
Description:
Algorithm:
Description:
A Prime number is a natural number greater than 1 that has no positive divisors other than 1
and itself. A natural number greater than 1 and that is not a prime number is called a composite
number.
Here, We are using a for loop and a break statement.
break:
break statement terminates the loop and resumes execution at the next statement, just like
the traditional break statement in C. The break statement can be used in both while and for loops.
If we are using break statement inside a nested loop, it stops the execution of the innermost
loop and start executing the next line of code after the block.
Step1: Start
Step2: Initialize sum = 0 and i = 2
Step3: Repeat Steps 4 to 13 while i < 2000000
Step4: Initialize c = 0
Step5: Check whether i is greater than 2 and i is divisible by 2 or not. If yes, goto Step6 else, goto Step7
Step6: Set c = 1 and goto Step12
Step7: Initialize j = 3
Step8: Repeat Steps 9 to 11 while j <= int(i**0.5)
Step9: Check whether i is divisible by j or not. If yes, goto Step10. Otherwise, goto Step11
Step10: Set c = 1 and goto Step12
Step11: Increment j by 2
Step12: Check whether c is 0 or not. If yes, goto Step13
Step13: Add i to the sum and store the result in sum
Step14: Display sum
Step15: Stop
Program:
print("To find sum of prime no's")
sum=0
for i in range(2,2000000):
flag=0
for j in range(2,i):
if i%j==0:
flag=1
if flag==0:
print(i)
sum=sum+i
print sum
No comments