68 lines
1.2 KiB
C
68 lines
1.2 KiB
C
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/* @author St\'efano Drimon Kurz M\'or */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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typedef struct _item_t {
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int value; // v_i
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int weight; // w_i
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float density; // v_i/w_i
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} item_t;
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int greater_f(const int x, const int y);
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int compare_f(const void *x, const void *y);
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int knapsack_f(const int n, const int M, const item_t * const itens) {
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int v = 0, w = 0;
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int r = 0;
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if (n < 1)
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return 0;
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while (M - w >= 0) {
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r = greater_f(r, v + knapsack_f(n - 1, M - w, &(itens[1])));
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v += itens[0].value;
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w += itens[0].weight;
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}
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return r;
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}
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int main(int argc, const char *argv[]) {
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int n;
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int M;
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item_t *itens;
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int i;
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scanf("%d %d", &n, &M);
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itens = (item_t*) calloc(n, sizeof(item_t));
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for (i = 0; i < n; ++i) {
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scanf("%d %d", &(itens[i].value), &(itens[i].weight));
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itens[i].density = (float) (itens[i].value) / itens[i].weight;
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}
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qsort(itens, (size_t) n, sizeof(item_t), compare_f);
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printf("%d\n", knapsack_f(n, M, itens));
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free(itens);
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return 0;
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}
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int greater_f(const int x, const int y) {
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return (x > y) ? x : y;
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}
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int compare_f(const void *x, const void *y) {
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return ((item_t*) x)->density - ((item_t*) y)->density;
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}
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