题目:
鸡翁一,值钱五,鸡母一,值钱三,鸡雏三,值钱一,N钱买N鸡,问翁、母、雏各几何?
一百个铜钱买了一百只鸡,其中公鸡一只5钱、母鸡一只3钱,小鸡一钱3只,问一百只鸡中公鸡、母鸡、小鸡各多少。
解题思路:
根据题意设x为公鸡,y为母鸡,z为小鸡,列方程x+y+z=N;5x+3y+(1/3)z=100即15x+9y+z=3N
为了减少程序运行的时间,对x、y、z的范围进行缩小,因为N钱最多买N/5只公鸡,N/3只母鸡,N只小鸡即:0 <= x <= N/5,0 <= y <=n/4,0 <= z <=N
代码:
#include "iostream"
using namespace std;
int main()
{
int n,m=1,count = 0;
int x,y,z;
while(cin>>n)
{
if(n==0)
break;
for(x=0;x<=n/5;x++)
for(y=0;y<=n/3;y++)
for(z=0;z<=n;z++)
if(15*x+9*y+z==(3*n)&&x+y+z==n)
count++;
cout<<"Case "<<m<<":";
if(count>0)
cout<<count<<endl<<endl;
else
cout<<"Not matched!"<<endl<<endl;
m++;
}
return 0;
}