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Description
Goldbach’s conjecture is one of the oldest unsolved problems in number theory and in all of mathematics. It states:Every even integer, greater than 2, can be expressed as the sum of two primes [1].
Now your task is to check whether this conjecture holds for integers up to 107.
Input
Input starts with an integer T (≤ 300), denoting the number of test cases.Each case starts with a line containing an integer n (4 ≤ n ≤ 107, n is even).
Output
For each case, print the case number and the number of ways you can express n as sum of two primes. To be more specific, we want to find the number of (a, b) where1) Both a and b are prime
2) a + b = n 3) a ≤ bSample Input
2 6 4 Sample Output Case 1: 1 Case 2: 1自己的模板总是差那么多内存,换了一个就过了。。。
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