Greedy Knapsack problem in c programming

[sourcecode language="c"]

/***********************************************************************/
/* Greedy Knapsack problem in c programming *
* Coded by Md. Mahedi Azad and presented by www.insafeta.com *
************************************************************************/
# include<stdio.h>

void knapsack(int n, float w[], float p[], float m){
float x[20], tp= 0;
int i, j, u;

for (i=0;i<n;i++){
x[i]=0.0;
}
u=m;
for (i=0;i<n;i++){
if(w[i]>u)
break;
else{
x[i]=1.0;
tp= tp+p[i];
u=u-w[i];
}
}

if(i<n){
x[i]=u/w[i];
}
tp= tp + (x[i]*p[i]);
printf("\n The path is: ");
for(i=0;i<n;i++){
printf("%f\t",x[i]);
}
printf("\n Maximum profit is: %f", tp);
}

float swap(float *a, float *b){
float temp;
temp= *a;
*a= *b;
*b= temp;
}

int main(){
float w[20], p[20], m;
int n, i ,j;
float ratio[20], temp;

printf ("\n Enter the number of objects: ");
scanf ("%d", &n);
printf ("\n Enter the weights and profits of each object: ");
for (i=0; i<n; i++){
scanf("%f %f", &w[i], &p[i]);
}

printf ("\nEnter the size of knapsack: ");
scanf ("%f", &m);
for (i=0; i<n; i++){
ratio[i]=p[i]/w[i];
}

for(i=0; i<n; i++){
for(j=i+1;j< n; j++){
if(ratio[i]<ratio[j]){
swap(&ratio[i], &ratio[j]);
swap(&w[i], &w[j]);
swap(&p[i], &p[j]);
}
}
}
knapsack(n, w, p, m);
}

[/sourcecode]