HDOJ 1397 Goldbach's Conjecture

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HDACM 1397

因为输入的值小于2^15，所以可以采用打表的方式来做。简单暴力

import java.util.Scanner;public class Main{    public static void main(String[] args) {        boolean noPrime[] = new boolean[32768];        for (int i = 2; i < noPrime.length; i++) {            if (!noPrime[i]) {                for (int j = i*2; j < noPrime.length; j+=i) {                    noPrime[j]=true;                }            }        }        Scanner sc = new Scanner(System.in);        while (sc.hasNext()) {            int n = sc.nextInt();            if (n==0) {                break;            }            int count = 0;            for (int i = 2; i <= n/2; i++) {                if (!noPrime[i]&&!noPrime[n-i]) {                    count++;                }            }            System.out.println(count);        }        sc.close();    }}

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