knapsack algorithm using c++

#include<iostream.h>

struct kru

{

  int i,p,w;

  float pr;

}g[10];

void main()

{

int n,j,k,wa;

float total=0;

struct kru temp;

cout<<"enter data ow W";

cin>>wa;

cout<<"Enter no.of nodes";

cin>>n;

cout<<"Enter for sum of calculation:";

for(j=0;j<n;j++)

{

g[j].i=j+1;

cout<<"i th profit =";

cin>>g[j].p;

cout<<"i th weight =";

cin>>g[j].w;

}

for(j=0;j<n;j++)

{

g[j].pr=g[j].p/float(g[j].w);

}

for(j=0;j<n;j++)

{

for(k=0;k<n;k++)

{

 if(g[j].pr<=g[k].pr)

 {

  temp=g[j];

  g[j]=g[k];

  g[k]=temp;

 }

}

}

for(j=0;j<n;j++)

{

  if(wa>=g[j].w)

  {

  total=total+g[j].p;

  wa=wa-g[j].w;

  }

  total=total+(g[j].pr*wa);

}

cout<<"total is "<<total;

}