求素数（Thinking in Java 4th Edition）

读到了Thinking in Java 4th Editon的第四章，遇到了求素数算法，记录一下。

Write a program to detect and print prime numbers (Integers evenly divisible only by themselves and 1), using two nested for loops and the modulus operator (%).

package control;

public class E04_FindPrimes {
public static void main(String[] args) {
int max = 100;
// Get the max value from the command line,
// if the argument has been provided:
if (args.length != 0) {
max = Integer.parseInt(args[0]);
}

for (int i = 1; i < max; i++) {
boolean prime = true;

for (int j = 2; j < i; j++) {
if (i % j == 0) {
prime = false;
}
}

if (prime) {
System.out.print(i + " ");
}
}
}
}

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