Fractional Knapsack Program in C

//Fractional Knapsack Problem is a Greedy Algorithm which
//helps in selecting specific items from a collection of items
//(the items can be fractioned)
//having specific weights and profits associated with them
//Under constraints of a sack capacity
//Such that the profit is maximum

#include<stdio.h>
int n,m;
double w[100],p[100];//arrays that will store weights and profits of items
double x[100];//Array that will store solution

//Before calling this function the elements must be sorted on the basis of
//decreasing profit by ratio
double fractional_knapsack(){
double profit;//for calculating max profit
int u,i;//u will keep track of capacity, i is a counter

//Initializing the solution vector to 0
for(i=0;i<n;i++){
x[i]=0.0;
}
u=m;
profit=0;
//Collecting whatever is possible until capacity allows
for(i=0;i<n;i++){
if(w[i]>u)
break;
x[i]=1;
profit+=p[i];
u-=w[i];
}

//Taking Fractions of the remaining elements
if(i<=n){
x[i]=(double)u/w[i];
profit+=(x[i]*p[i]);
}
return profit;
}


//Function that Sorts on the basis of Profit by Ratio
//(Using Insertion Sort)

void sortProfitByRatio(){
double profit_ratio_array[100]={0.0};
int i,j,temp,temp1,temp2;
for(i=0;i<n;i++){
profit_ratio_array[i]=p[i]/w[i];
}
for(i=1;i<n;i++){
temp=profit_ratio_array[i];
temp1=w[i];
temp2=p[i];

for(j=i-1;j>=0;j--){
if(profit_ratio_array[j]<temp){
profit_ratio_array[j+1]=profit_ratio_array[j];
w[j+1]=w[j];
p[j+1]=p[j];
}
else
break;
}
profit_ratio_array[j+1]=temp;
w[j+1]=temp1;
p[j+1]=temp2;

}
}


void main(){
int i;
double pr;
printf("Enter the no of elements ");
scanf("%d",&n);
printf("Enter the capacity ");
scanf("%d",&m);
printf("Enter the weights and corresponding profits of the elements \n");
for(i=0;i<n;i++)
scanf("%lf %lf",&w[i],&p[i]);
sortProfitByRatio();
printf("After Sorting \n");
for(i=0;i<n;i++)
printf("%lf %lf \n",w[i],p[i]);
pr=fractional_knapsack();
printf("Total profit is %lf\n",pr);
printf("Solution Vector\n");
for(i=0;i<n;i++)
printf("Item wt: %lf Quantity Taken: %lf\n",w[i],x[i]);
}