Homework

import java.util.Arrays;
import java.util.Scanner;

public class _t381 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		while(in.hasNext()){
			int m=in.nextInt(),n=in.nextInt();
			if(m==0 && n==0) break;
			int[] times=new int[m];
			int[] vals=new int[m];
			double[] avgs=new double[m];
			for (int i = 0; i < m; i++) {
				times[i]=in.nextInt();
				vals[i]=in.nextInt();
				avgs[i]=vals[i]*1.0/times[i];
			}
			
			double dtemp=0;
			int itemp=0;
			for (int i = 0; i < m-1; i++) {
				for (int j = 0; j < m-1; j++) {
					if(avgs[j]<avgs[j+1]){
						dtemp=avgs[j];
						avgs[j]=avgs[j+1];
						avgs[j+1]=dtemp;
						
						itemp=vals[j];
						vals[j]=vals[j+1];
						vals[j+1]=itemp;
						
						itemp=times[j];
						times[j]=times[j+1];
						times[j+1]=itemp;
					}
				}
			}
//			System.out.println(Arrays.toString(avgs));
			
			int sumT=0;
			double sumV=0;
			for (int i = 0; i < m; i++) {
				if(sumT<=n){
					sumT+=times[i];
					sumV+=vals[i];
					if(i==m-1 && sumT>n){
						sumV-=vals[i];
						sumT-=times[i];
					}
				}
				else{
					sumV-=vals[--i];
					sumT-=times[i];
				}
			}
//			System.out.println(sumT);
			System.out.printf("%.2f\n",sumV);
		}
	}
}

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while (sc.hasNext()) {
			int m = sc.nextInt();
			int n = sc.nextInt();
			if(m == 0 && n == 0) break;
			Paper[] papers = new Paper[m];
			for (int i = 0; i < m; i ++ ) {
				papers[i] = new Paper(sc.nextDouble(), sc.nextDouble());
			}
			Arrays.sort(papers);
			double sum = 0;
			for (int i = 0; i < papers.length; i ++ ) {
				if(papers[i].time > n) {
					sum += n * papers[i].perValue;
					break;
				}
				sum += papers[i].value;
				n -= papers[i].time;
			}
			System.out.printf("%.2f\n", sum);
		}
	}

	static class Paper implements Comparable<Paper> {
		double time;
		double value;
		double perValue;

		public Paper(double time, double value) {
			this.time = time;
			this.value = value;
			this.perValue = value / time;
		}

		@Override
		public int compareTo(Paper o) {
			return o.perValue > this.perValue ? 1 : - 1;
		}
	}
}

#include<stdio.h>
#include<iostream>
#include<stdlib.h>
#include<algorithm>
using namespace std;
struct O {
	double t, v,rate;
};
bool cmp(O o1, O o2) {
	return o1.rate > o2.rate;
}


int main(int argc, char* argv[])
{
	int m, n, i;
	double ans = 0;
	struct O o[21];
	while(cin>>m>>n && (m || n)) {
		ans = 0;
		for(i = 0; i < m; ++i) {
			cin>>o[i].t>>o[i].v;

			o[i].rate = o[i].v/o[i].t;
		}

	/*	cout<<"输入完毕"<<endl;
	*/	sort(o, o+m, cmp);

	/*	cout<<"排序完毕"<<endl;
	*/	for(i = 0; i < m; ++i) {
			if(n - o[i].t >= 0) {
				ans += o[i].v;
				n -= o[i].t;
			}else {
				ans += n * o[i].rate;
				break;
			}
			
		}


		printf("%0.2lf\n", ans);
	}

	return 0;
}

while(cin>>m>>n && (m||n))

while(cin>>m>>n && m && n)

T，V

#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
using namespace std;

struct Paper
{
	int time;
	int value;
	double perValue;
	bool operator<(const Paper & h) const
	{
		return (h.perValue < perValue);
	}
};

int main()
{
	int M, N;
	while (cin >> M >> N && (M || N))
	{
		vector<Paper> list(M);
		for (int i = 0; i < M; ++i)
		{
			cin >> list[i].time >> list[i].value;
			list[i].perValue = list[i].value / double(list[i].time);
		}

		sort(list.begin(), list.end());
		double sum = 0;
		for (int i = 0; i < M; ++i)
		{
			if (N >= list[i].time)
			{
				sum += list[i].value;
				N -= list[i].time;
			}
			else
			{
				sum += list[i].perValue * N;
				break;
			}
		}

		cout << setiosflags(ios::fixed) << setprecision(2) << sum << endl;
	}

	return 0;
}