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Find nth Prime Number in C++

c++ program to find prime numbers: The problem of finding prime number can be solved by checking all numbers, testing them for prime and then moving ahead. If you want to calculate nth prime. Then this can be done in a brutal way by checking the number one by one. This may sound odd, by there is no easy way then this  for prime numbers (Well Actually there are like Pollard's Rho Algorithm, Number Sieves or Shor's Quantum Algorithm, but we are talking about the one that most people may understand easily). There may be way to pre-calculate the prime numbers but that again is not sufficient. So how can we use c++ to create a program to find prime numbers.
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Program to find nth Prime number in C

Objective: To print any Prime number in C.  This task may sound easy but is a very good exercise to help optimize CPU intensive programs. Finding Prime number is a very CPU hogging task and it becomes even more dreaded as the number starts to grow. Lets say we want to find 30001th prime. how will we find it?? Here is the program. Programming logic : The easiest method is to check if the given number N is divisible by any number from 2 to N-1. But it may be noted that we don't need to go beyond the number that is square root of N.  why?? lets have a look. Say we are testing number 49 for prime number. Our objective is to find any number that may divide it. so we start from 2,3,4 etc. As soon as we cross 7 there will be no number that will divide 49, if there was we have got it earlier since it will be smaller then 7.  Get it? another example 64 : 2x32 4x16 8x8 16x4 32x2 as you can see when we pass number 8 we don't need to test as the number that will come ,...
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