用贪心算法求解普通背包问题的C++代码

#include<iostream.h>
#define M 100
void display(int &n,double &C,double s[M],double p[M])
{
int i;
cout<<"请输入物体数n:";
cin>>n;
cout<<endl;
cout<<"请输入背包总容量C:";
cin>>C;
cout<<endl;
cout<<"请输入各物体的大小或重量:"<<endl;
s[0]=0;
for(i=1;i<=n;i++)
cin>>s[i];
cout<<"请输入各物体的价值p:"<<endl;
p[0]=0;
for(i=1;i<=n;i++)
cin>>p[i];
};
void asc(int n,double s[M],double p[M])//按照价值密度的降序排列；
{
int i,j;
double temp1,temp2,temp3,c[M];
for(i=1;i<=n;i++)
c[i]=p[i]/s[i];
for(i=1;i<n;i++)
for(j=1;j<=n-i;j++)
if(c[j]<c[j+1])
{
temp1=p[j];p[j]=p[j+1];p[j+1]=temp1;
temp2=s[j];s[j]=s[j+1];s[j+1]=temp2;
temp3=c[j];c[j]=c[j+1];c[j+1]=temp3;
}
};
void knapsack(int n,double C,double s[M],double p[M],double x[M])//,double totalp)
{
int i;
double c1;
asc(n,s,p);
c1=C;
while(c1!=0)
{
for(i=1;i<=n;i++)
{
if(s[i]<=c1)
{
x[i]=1;
c1=c1-s[i];
}
else if(s[i]>c1)
{
x[i]=c1/s[i];
c1=0;
}
// totalp=totalp+p[i]*x[i];
}
}
};
void main()
{
int i,n;
double C=0,totalp=0,s[M],p[M],x[M];
char ch;
while(1)
{
display(n,C,s,p);
knapsack(n,C,s,p,x);//,totalp);
cout<<"结果表示为:"<<endl;
for(i=1;i<=n;i++)
cout<<"第"<<i<<"个物体大小:"<< s[i]<<" 物体价值:"<< p[i]<<" 物体价值密度:"<< p[i]/s[i]<<" "<<endl;
cout<<endl;
// for(i=1;i<=n;i++)
// cout<<"第"<<i<<"个物体价值:"<< p[i]<<" "<<endl;
// cout<<endl;
cout<<"向量表示:"<<" ( ";
for(i=1;i<=n;i++)
{
cout<<x[i]<<" ";
totalp=totalp+p[i]*x[i];
}
cout<<")"<<endl;
cout<<"背包的总价值为："<<totalp<<endl; //背包所装载总重量
cout<<"按Y或y继续操作，否则按任意键"<<endl;
cin>>ch;
if(ch=='Y'||ch=='y')
continue;
else
break;
}
}