洛谷P1080 国王游戏

题目链接：https://www.luogu.org/problem/P1080

该题贪心策略直接将左手金币数*右手金币数小的排在前面即可

为什么这样洛谷题解讲的很清楚了

这篇题解只为属性java大数使用，够直接照搬了大佬的代码

import java.math.BigInteger;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

//表示一个大臣
class Minister {

    private int left;
    private int right;

    public Minister(int left, int right) {
        this.left = left;
        this.right = right;
    }

    public int getLeft() {
        return left;
    }

    public void setLeft(int left) {
        this.left = left;
    }

    public int getRight() {
        return right;
    }

    public void setRight(int right) {
        this.right = right;
    }

}

public class Main {

    //数据量不大 出于偷懒考虑直接用Scanner
    Scanner scanner = new Scanner(System.in);
    //题目所述的n
    int n;
    //存储各个大臣所对应的数据 0下标对应国王
    Minister ministers[];

    public void input() {
        n = scanner.nextInt();
        ministers = new Minister[n + 1 + 1];
        for (int i = 0; i <= n; i++) {
            ministers[i] = new Minister(scanner.nextInt(), scanner.nextInt());
        }
    }

    public void process() {
        //对大臣进行排序 为什么要这样下面的cpp大佬们已经说的很清楚了
        //Arrays.sort(T[],a,b,Comparator) 对[a,b)区间进行排序
        Arrays.sort(ministers, 1, n + 1, new Comparator() {
            @Override
            public int compare(Minister o1, Minister o2) {
                return (o1.getLeft() * o1.getRight() - o2.getLeft() * o2.getRight());
            }
        });
        //计算到第i个大臣的时候 之前所有大臣左手上的数字的乘积(包括国王)
        //题外话:为什么BigInteger没有BigInteger(int source)这个构造函数..
        BigInteger prev = new BigInteger(String.valueOf(ministers[0].getLeft()));
        //计算到第i个大臣时 前面所有大臣中所获的金钱最多的数目
        BigInteger max = BigInteger.ZERO;
        for (int i = 1; i <= n; i++) {
            //特判 如果当前大臣所获得的金钱不足1 则改为1
            if (prev.compareTo(new BigInteger(String.valueOf(ministers[i].getRight()))) < 0) {
                if (new BigInteger("1").compareTo(max) > 0) {
                    max = new BigInteger("1");
                }
            } else {

                BigInteger int1 = prev.divide(new BigInteger(String.valueOf(ministers[i].getRight())));
                if (int1.compareTo(max) > 0) {
                    max = int1;
                }
            }
            prev = prev.multiply(new BigInteger(String.valueOf(ministers[i].getLeft())));
        }
        System.out.println(max);
    }

    public static void main(String[] args) {
        Main app = new Main();
        app.input();
        app.process();
    }

}

 

转载于:https://www.cnblogs.com/qingjiuling/p/11589328.html