Initial Commit - days 01-12

day07/ex1-c.c

@@ -0,0 +1,233 @@
+/* ex1-c: Advent2020 game, day 7/game 1
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct node {
+    struct chain *chain;
+    struct node *next;
+    int num;
+    //int taken;
+};
+
+struct chain {
+    char key[80];               /* arbitrary, to avoid multiple mallocs.
+                                   char* would be better */
+    struct chain *next;         /* if collision */
+    struct node *contains;      /* bags contained */
+    struct node *isin;          /* is part of */
+    int taken;
+};
+
+#define HASH_SIZE 1024
+static struct chain *thehash[HASH_SIZE];
+static nkeys=0;
+
+unsigned long get_hash(str)
+    char *str;
+{
+    register unsigned long hash = 5381;
+    register int c;
+
+    while (c = *str++)
+        hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+    return hash;
+}
+
+struct chain *find_key(key)
+    char *key;
+{
+    unsigned long hash;
+    struct chain *entry;
+
+    hash=get_hash(key)%HASH_SIZE;
+    entry=thehash[hash];
+    while (entry) {
+        if (!strcmp(key, entry->key))
+            break;
+        entry=entry->next;
+    }
+    return entry;
+}
+
+struct chain *insert_key(key)
+    char *key;
+{
+    unsigned long hash;
+    struct chain *entry;
+
+    if (!(entry=find_key(key))) {
+        hash=get_hash(key)%HASH_SIZE;
+        entry=malloc(sizeof (struct chain));
+
+        strcpy(entry->key, key);
+        entry->next=thehash[hash];
+        thehash[hash]=entry;
+
+        entry->contains=NULL;
+        entry->isin=NULL;
+        entry->taken=0;
+        nkeys++;
+    }
+    return entry;
+}
+
+void insert_node(container, contained, num)
+    struct chain *container;
+    struct chain *contained;
+    int num;
+{
+    struct node *node;
+
+    node=malloc(sizeof node);
+    node->chain=contained;
+    node->num=num;
+    //node->taken=0;
+    node->next=container->contains;
+    container->contains=node;
+
+    node=malloc(sizeof node);
+    node->chain=container;
+    node->num=0;
+    //node->taken=0;
+    node->next=contained->isin;
+    contained->isin=node;
+}
+
+void print_node_list(node)
+    struct node*node;
+{
+    while (node) {
+        printf("\t\t%d %s", node->num, node->chain->key);
+        node=node->next;
+    }
+    printf("\n");
+
+}
+
+int count_containers(chain)
+    struct chain *chain;
+{
+    struct chain *p;
+    struct node *node;
+    int i=0;
+
+    node = chain->isin;
+    while (node) {
+        p=node->chain;
+        if (p->taken == 0) {
+            i++;
+            p->taken=1;
+            i+=count_containers(p);
+        }
+        node=node->next;
+    }
+    chain->taken=1;
+    return i;
+}
+int count_contained(chain)
+    struct chain *chain;
+{
+    struct chain *p;
+    struct node *node;
+    int i=1, num;
+
+    node = chain->contains;
+    while (node) {
+        p=node->chain;
+        num=node->num;
+        i+=num*count_contained(p);
+        node=node->next;
+    }
+    return i;
+}
+
+void print_keys()
+{
+    int i, j;
+    struct chain *chain;
+    struct node *node;
+
+    for (i=0; i<HASH_SIZE; ++i) {
+        chain=thehash[i];
+        j=0;
+        while (chain) {
+            printf("%d: %d=[%s]\n", i, j, chain->key);
+            node=chain->contains;
+            if (node) {
+                printf("\tCONTAINS:");
+                print_node_list(node);
+            }
+
+            node=chain->isin;
+            if (node) {
+                printf("\tIS IN:");
+                print_node_list(node);
+            }
+
+            chain=chain->next;
+            j++;
+        }
+    }
+}
+
+char*sep=" \t\n";               /* separator */
+
+char *getcolor(line)
+    char *line;
+{
+    static char buf[80], *tok, *ret=NULL;
+
+    if (tok=strtok(line, sep)) {
+        strcpy(buf, tok);
+        if (tok=strtok(NULL, sep)) {
+            ret=strcat(buf, tok);
+        }
+    }
+    return ret;
+}
+
+int main(ac, av)
+    int ac;
+    char **av;
+{
+    int num=0, count=0;
+    char line[512], *color, *numstr;
+    struct chain *entry, *isin;
+
+    if (ac != 2) {
+        fprintf(stderr, "usage: %s key\n", *av);
+        exit (1);
+    }
+    while (fgets(line, sizeof line, stdin)) {
+        count++;
+        if (!(color=getcolor(line))) {
+            continue;
+        }
+        entry=insert_key(color);
+
+        // skip "bag" and "contain"
+        strtok(NULL, sep);
+        strtok(NULL, sep);
+
+        while (numstr=strtok(NULL, sep)) {
+            if (num=atoi(numstr)) {
+                color=getcolor(NULL);
+                isin=insert_key(color);
+                insert_node(entry, isin, num);
+                strtok(NULL, sep);
+            }
+        }
+
+        continue;
+    }
+    //print_keys();
+    entry=find_key(*(av+1));
+    //num=count_contained(entry)-1; /* ex 2 */
+    num=count_containers(entry); /* ex 1 */
+
+    printf("%s : target=%s nkeys=%d res=%d\n", *av, *(av+1), nkeys, num);
+    exit (0);
+}