c語言計算ab區間所有素數

篩法求［a，b］中的素數。

Find out the prime numbers in [a， b].

輸入：

2個正整數：a b。

a、b均在1000以內，且a小於等於b。

2 positive integers: a， b. Both a and b are less than or equal 1000 and a is less than or equal to b.

輸出：

[a b]區間內的所有素數，每個單獨一行。

All primes in [a， b]， each one in a row.