HDU 1009 FatMouse' Trade

FatMouse' Trade

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 53861    Accepted Submission(s): 18013

Problem Description

FatMouse prepared M pounds of cat food, ready to trade with the cats guarding the warehouse containing his favorite food, JavaBean.
The warehouse has N rooms. The i-th room contains J[i] pounds of JavaBeans and requires F[i] pounds of cat food. FatMouse does not have to trade for all the JavaBeans in the room, instead, he may get J[i]* a% pounds of JavaBeans if he pays F[i]* a% pounds of cat food. Here a is a real number. Now he is assigning this homework to you: tell him the maximum amount of JavaBeans he can obtain.

 

Input

The input consists of multiple test cases. Each test case begins with a line containing two non-negative integers M and N. Then N lines follow, each contains two non-negative integers J[i] and F[i] respectively. The last test case is followed by two -1's. All integers are not greater than 1000.

 

Output

For each test case, print in a single line a real number accurate up to 3 decimal places, which is the maximum amount of JavaBeans that FatMouse can obtain.

 

Sample Input

5 37 24 35 220 325 1824 1515 10-1 -1

 

Sample Output

13.33331.500
#include<stdio.h>#include<string.h>typedef struct {    double cat,bean;    double per;}Trade;void Sort(Trade* tra,int n){    int i,j,log;    double max;    Trade temp;    for(i=0;i<n-1;i++)    {        max=tra[i].per,log=i;        for(j=i+1;j<n;j++)        {            if(max<tra[j].per)            {                max=tra[j].per;                log=j;            }        }        if(log!=i)        {            temp=tra[i];            tra[i]=tra[log];            tra[log]=temp;        }    }}int main(){    int m,n,i;    double s;    Trade tra[1000];    while(1)    {        s=0;        scanf("%d %d",&m,&n);        if(m==n&&m==-1) break;        for(i=0;i<n;i++)        {            scanf("%lf %lf",&tra[i].cat,&tra[i].bean);            tra[i].per=tra[i].cat/tra[i].bean;        }        Sort(tra,n);        for(i=0;i<=n-1;i++)          {              if(m>=tra[i].bean)              {                  s=s+tra[i].cat;                  m=m-(int )tra[i].bean;              }              else              {                  s=s+tra[i].per*m;                  break;              }          }         printf("%.3f\n",s);    }    return 0;}