Knapsacks problem 1/0 dynamic - c

Question

I want to solve the knapsack problem with dynamic programming! The item should be in the knapsack or not, I do not want to put the same item in the knapsack more then one time!
I've looked at this code but with this one you can add the same object more then just one time
#include <stdio.h>
#define MAXWEIGHT 100
int n = 3; /* The number of objects */
int c[10] = {8, 6, 4}; /* c[i] is the *COST* of the ith object; i.e. what
YOU PAY to take the object */
int v[10] = {16, 10, 7}; /* v[i] is the *VALUE* of the ith object; i.e.
what YOU GET for taking the object */
int W = 10; /* The maximum weight you can take */
void fill_sack() {
int a[MAXWEIGHT]; /* a[i] holds the maximum value that can be obtained
using at most i weight */
int last_added[MAXWEIGHT]; /* I use this to calculate which object were
added */
int i, j;
int aux;
for (i = 0; i <= W; ++i) {
a[i] = 0;
last_added[i] = -1;
}
a[0] = 0;
for (i = 1; i <= W; ++i)
for (j = 0; j < n; ++j)
if ((c[j] <= i) && (a[i] < a[i - c[j]] + v[j])) {
a[i] = a[i - c[j]] + v[j];
last_added[i] = j;
}
for (i = 0; i <= W; ++i)
if (last_added[i] != -1)
printf("Weight %d; Benefit: %d; To reach this weight I added object %d (%d$ %dKg) to weight %d.\n",
i, a[i], last_added[i] + 1, v[last_added[i]],
c[last_added[i]], i - c[last_added[i]]);
else
printf("Weight %d; Benefit: 0; Can't reach this exact weight.\n", i);
printf("---\n");
aux = W;
while ((aux > 0) && (last_added[aux] != -1)) {
printf("Added object %d (%d$ %dKg). Space left: %d\n",
last_added[aux] + 1, v[last_added[aux]],
c[last_added[aux]], aux - c[last_added[aux]]);
aux -= c[last_added[aux]];
}
printf("Total value added: %d$\n", a[W]);
}
int main(int argc, char *argv[]) {
fill_sack();
return 0;
}
and then i tried to make a array to see if the object is in the knapsack or not, but then this program did not work as it should!
#define MAXWEIGHT 101
#define MAX_ITEMS 100000
int items = 2;
int c[10] = {1, 2};
int v[10] = {1000, 2001};
int W = 100;
int taken[MAX_ITEMS];
void takenOrNot(){
int i;
for(i = 0; i < items; i++){
taken[i] = 0;
}
}
void fill_sack() {
int a[MAXWEIGHT];
int last_added[MAXWEIGHT];
int i, j;
int aux;
for (i = 0; i <= W; ++i) {
a[i] = 0;
last_added[i] = -1;
}
a[0] = 0;
for (i = 1; i <= W; ++i)
for (j = 0; j < items; ++j)
if ((c[j] <= i) && (a[i] < a[i - c[j]] + v[j]) && taken[j] == 0) {
a[i] = a[i - c[j]] + v[j];
last_added[i] = j;
taken[j] = 1;
}
for (i = 0; i <= W; ++i)
if (last_added[i] != -1)
printf("Weight %d; Benefit: %d; To reach this weight I added object %d (%d$ %dKg) to weight %d.\n",
i, a[i], last_added[i] + 1, v[last_added[i]],
c[last_added[i]], i - c[last_added[i]]);
else
printf("Weight %d; Benefit: 0; Can't reach this exact weight.\n", i);
printf("---\n");
aux = W;
while ((aux > 0) && (last_added[aux] != -1)) {
printf("Added object %d (%d$ %dKg). Space left: %d\n",
last_added[aux] + 1, v[last_added[aux]],
c[last_added[aux]], aux - c[last_added[aux]]);
aux -= c[last_added[aux]];
}
printf("Total value added: %d$\n", a[W]);
}
int main(int argc, char *argv[]) {
takenOrNot();
fill_sack();
return 0;
}
Could you guys help me please? :)

Answer 1

This might help...!
public class Knapsack
{
int knapsackSize;
int[] _weights;
int[] _values;
int[,] results;
public Knapsack(int[] weights, int[] values, int size)
{
_weights = weights;
_values = values;
knapsackSize = size;
}
public int CreateSolution()
{
results = new int[_weights.Length + 1, knapsackSize + 1];
for (int i = 0; i < _weights.Length; i++) // item 1 to n
{
for (int j = 1; j <= knapsackSize; j++) //weight 1 to m
{
if (_weights[i] > j)
{
//if item weight is grater than knapsack capacity
results[i + 1, j] = results[i, j];
}
else
{
if (results[i, j] > (_values[i] + results[i, j - _weights[i]]))
{
//if previously calculated value only is grater
results[i + 1, j] = results[i, j];
}
else
{
//if including current item gives more value
results[i + 1, j] = _values[i] + results[i, j - _weights[i]];
}
}
}
}
return results[_weights.Length, knapsackSize]; // index (n, m) will be max value
}
static void Main(string[] args)
{
Knapsack demo = new Knapsack(new int[] { 23, 26, 20, 18, 32, 27, 29, 26, 30, 27 }, new int[] { 505, 352, 458, 220, 354, 414, 498, 545, 473, 543 }, 67);
Console.WriteLine("Solution is: " + demo.CreateSolution());
Console.ReadLine();
}
}