RosettaCodeData/Task/Knapsack-problem-Unbounded/C/knapsack-problem-unbounded.c

59 lines
1.3 KiB
C

#include <stdio.h>
#include <stdlib.h>
typedef struct {
char *name;
double value;
double weight;
double volume;
} item_t;
item_t items[] = {
{"panacea", 3000.0, 0.3, 0.025},
{"ichor", 1800.0, 0.2, 0.015},
{"gold", 2500.0, 2.0, 0.002},
};
int n = sizeof (items) / sizeof (item_t);
int *count;
int *best;
double best_value;
void knapsack (int i, double value, double weight, double volume) {
int j, m1, m2, m;
if (i == n) {
if (value > best_value) {
best_value = value;
for (j = 0; j < n; j++) {
best[j] = count[j];
}
}
return;
}
m1 = weight / items[i].weight;
m2 = volume / items[i].volume;
m = m1 < m2 ? m1 : m2;
for (count[i] = m; count[i] >= 0; count[i]--) {
knapsack(
i + 1,
value + count[i] * items[i].value,
weight - count[i] * items[i].weight,
volume - count[i] * items[i].volume
);
}
}
int main () {
count = malloc(n * sizeof (int));
best = malloc(n * sizeof (int));
best_value = 0;
knapsack(0, 0.0, 25.0, 0.25);
int i;
for (i = 0; i < n; i++) {
printf("%d %s\n", best[i], items[i].name);
}
printf("best value: %.0f\n", best_value);
free(count); free(best);
return 0;
}