C Program to implement Knapsack using Greedy technique.

#include<stdio.h>

#include<conio.h>

void knapsack(int n,float profit[],float weight[],float capacity){

 float x[20],total,tp=0;

 int i,j;

 total=capacity;

 printf("\nEntered Items are :\n ");

 printf(" Value\t\t\tProfit:");

 printf("\n---------------------------\n");

 for(i=0;i<n;i++){

     printf("%f\t\t\t%f\n",profit[i],weight[i]);

   }

 for(i=0;i<n;i++)

     x[i]=0.0;

 for(i=0;i<n;i++){

   if(weight[i]>total)

      break;

   else

       {

           x[i]=1.0;

           tp+=profit[i];

           total-=weight[i];

       }

    }

   if(i<n){

      x[i]=total/weight[i];

   }

   tp+=x[i]*profit[i];

   printf("\n\nProfit Vector is : ");

   for(i=0;i<n;i++)

     printf("%f\t",x[i]);

   printf("\n");

   printf("\nTotal Profit : %f",tp);

}

int main(){

  float weight[20],profit[20],ratio[20],capacity,temp;

  int n,i,j;

  printf("\nEnter no of items : ");

  scanf("%d",&n);

  printf("\nEnter Capacity : ");

  scanf("%f",&capacity);

  printf("\nEnter Weight nd Profit : ");

  for(i=0;i<n;i++){

      printf("\nEnter Weight nd Profit for item[%d] : ",i);

      scanf("%f %f",&weight[i],&profit[i]);

  }

  for(i=0;i<n;i++)

    ratio[i]=profit[i]/weight[i];

  for(i=0;i<n;i++)

     for(j=i+1;j<n;j++){

       if(ratio[i]<ratio[j]){

        temp=ratio[j];

        ratio[j]=ratio[i];

        ratio[i]=temp;

        temp=weight[j];

        weight[j]=weight[i];

        weight[i]=temp;

        temp=profit[j];

        profit[j]=profit[i];

        profit[i]=temp;

       }

       knapsack(n,profit,weight,capacity);

       getch();

       return(0);

     }

                            }

Input/Output: