java输出所有的勾股数

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;

/**
 * @Author hucy
 * @Date 2022/4/7 19:40
 * @Version 1.0
 */
public class GouguHashMap {
    public static int gougu(int n ) throws IOException {
        File f = new File("D:/GouGuNums.txt");
        FileWriter fw = new FileWriter(f);
        HashMap<Integer, Integer> map = new HashMap<>();
        for (int i = 5; i <= n; i++) {
            map.put(i*i,i);
        }
        int cnt =0;
        int m = (int) (n/1.4);
        for (int i = 3; i < m; i++) {
            for (int j = i+1;j < n;j++){
                int N = i*i+j*j;
                if (map.containsKey(N)){
                    fw.write("["+i+", "+j+", "+map.get(N)+"]"+"\t");
                    if ((cnt++ & 7) ==7){
                        fw.write("\n\n");
                    }
                }
            }
        }
        fw.close();
        return cnt;
    }

    public static void main(String[] args) throws IOException {

        long start = System.currentTimeMillis();
        System.out.println(gougu(1000));
        long end = System.currentTimeMillis();
        System.out.println(end -start);
    }


}