#include <stdio.h>int N = 5;int maxKnown[18];typedef struct {int size; int val;}Item;Item  itemKnown[18];Item items[5];int knap(int cap)  { int i, space, max, t;    for (i = 0, max = 0; i < N; i++)      if ((space = cap-items[i].size) >= 0)        if ((t = knap(space) + items[i].val) > max)           max = t;    return max;       }int main(){     items[0].size= 3;   items[1].size= 4;   items[2].size= 7;   items[3].size = 8;   items[4].size = 9;   items[0].val= 4;   items[1].val = 5;   items[2].val = 10;   items[3].val = 11;   items[4].val = 13;   printf("%d\n",knap(40));}