算法（第4版）2.4.25计算数论

package 排序.优先队列;

import java.util.Scanner;

public class CubeSum implements Comparable<CubeSum>{
 private int i;
 private int j;
 private int sum;
 private CubeSum(int i,int j){
 this.sum=i*i*i+j*j*j;
 this.i=i;
 this.j=j;
 }
 public String toString(){
 return ("("+sum+","+i+","+j+")");
 }
 public static void main(String args[]){
 Scanner sc=new Scanner(System.in);
 int N=sc.nextInt();
 MinPQ <CubeSum>pq=new MinPQ<CubeSum>(N);
 for(int i=0;i<=N;i++) {
 pq.insert(new CubeSum(i, 0));
 }
 while(!pq.isEmpty()){
 CubeSum s=pq.delMin();
 System.out.print(s+" ");
 if(s.j<N) {
 pq.insert(new CubeSum(s.i, s.j+1)); 　　　　　　//此处从https://algs4.cs.princeton.edu/24pq/CubeSum.java.html引入，感觉该方法收益很多
 }
 }
 }
 @Override
 public int compareTo(CubeSum that) {
 if(this.sum<that.sum)return -1;
 if(this.sum>that.sum)return +1;
 return 0;
 }
}