Loner John 的博客
0%

csuoj-算法-MoonCake

发表于 更新于 分类于 Valine：

题目

解题思路

计算每种月饼的单价，贪心选择单价高的。

C++代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
#include<iostream>
#include<algorithm>
using namespace std;
struct mooncake {
    double s;
    double v;
    double vt;
};

bool cmp(mooncake o1,mooncake o2){
	return o1.vt<o2.vt;
}

int main()
{
    int N;
    double D;
 
    scanf("%d%lf",&N,&D);
    mooncake list[N+1];
    for(int i = 0;i < N;i++){
        scanf("%lf", &list[i].s);
    }
    for(int i = 0;i <N;i++){
        scanf("%lf",&list[i].v);
        list[i].vt = list[i].v/list[i].s;
    }
    sort(list,list+N,cmp);
    double ans = 0;
    for(int i = N-1;i>=0;i--){
        if(list[i].s<=D){
            D-=list[i].s;
            ans+=list[i].v;
        }
        else{
            ans+=list[i].vt*D;
            break;
        }
    }
    printf("%.2f\n",ans);
    return 0;
}

Java代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
//不知道为什么，JAVA代码过不去。
	import java.util.ArrayList;
	import java.util.Comparator;
	import java.util.Scanner;
	
	public class Main {
	    public static void main(String[] args) {
	        Scanner scanner = new Scanner(System.in);
	        while (scanner.hasNext()){
	            int N = scanner.nextInt();
	            int D = scanner.nextInt();
	            class MoonCake {
	                double s;
	                double v;
	                double vt;
	
	                MoonCake(int s) {
	                    this.s = s;
	                }
	                double getVt() {
	                    return vt;
	                }
	            }
	            ArrayList<MoonCake> list = new ArrayList<>(N);
	            for (int i = 0; i < N; i++) {
	                list.add(new MoonCake(scanner.nextInt()));
	            }
	            for (MoonCake moonCake : list) {
	                moonCake.v = scanner.nextInt();
	                moonCake.vt = moonCake.v / moonCake.s;
	            }
	            list.sort(Comparator.comparingDouble(MoonCake::getVt));
	
	            double ans = 0;
	            for (int i = N - 1; i >= 0; i--) {
	                MoonCake moonCake = list.get(i);
	                if (moonCake.s <= D) {
	                    D -= moonCake.s;
	                    ans += moonCake.v;
	                } else {
	                    ans += moonCake.vt * D;
	                    break;
	                }
	            }
	            System.out.printf("%.2f", ans);
	        }
	    }
	}