HDU 1.3.1 FatMouse' Trade

FatMouse' Trade

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4921 Accepted Submission(s): 1476 

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 <stdlib.h>  int main()  {  int M, N;  while (scanf("%d%d", &M, &N) != EOF)  {  int i, j, J[1000], F[1000], temp1;  double ratio[1000], JavaBeans = 0, temp;  if ((M == -1) && (N == -1))  {  return 0;  }  for (i = 0; i<N; i++)  {  scanf("%d%d", &J[i], &F[i]);  ratio[i] = (J[i] * 1.0) / F[i];  }  for (i = 0; i<N; i++)  {  for (j = 0; j<N - i - 1; j++)  {  if (ratio[j]<ratio[j + 1])  {  temp = ratio[j];  ratio[j] = ratio[j + 1];  ratio[j + 1] = temp;  temp1 = F[j];  F[j] = F[j + 1];  F[j + 1] = temp1;  temp1 = J[j];  J[j] = J[j + 1];  J[j + 1] = temp1;  }  }  }  for (i = 0; i<N; i++)  {  if (M >= F[i])  {  JavaBeans = J[i] + JavaBeans;  M = M - F[i];  }  else  {  JavaBeans = JavaBeans + ratio[i] * M;  break;  }  }  printf("%.3lf\n", JavaBeans);  }  return 0;  }