23 lines
562 B
Python
23 lines
562 B
Python
#TO CHECK WHETHER A NUMBER IS PRIME OR NOT
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def isPrime(N):
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if N<=1:
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return False
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for i in range(2, int(N**0.5) + 1):
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if N%i==0:
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return False
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return True
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# TIME COMPLEXITY - O(sqrt(N))
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# EXAMPLES
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# print(isPrime(3)) -> True
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# print(isPrime(15)) -> False
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# We are just checking till sqrt(N) as if their is any factor of a number
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# greater than sqrt(N) then it's partner will be less than sqrt(N) as if a*b>N
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# and a>=sqrt(N) then b<=sqrt(N) as if b>sqrt(N) then a*b>N.
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