First fully working version

1 files changed, 163 insertions, 0 deletions

diff --git a/cover.c b/cover.c
new file mode 100644
index 0000000..b5b1b9c
--- /dev/null
+++ b/cover.c
@@ -0,0 +1,163 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "cover.h"
+
+element* insert_element(set* s, int id) {
+    element* el = malloc(sizeof(element));
+    el->id = id;
+    el->set = s;
+    el->prev = el->next = NULL;
+    if (s->head) {
+        el->next = s->head;
+        s->head->prev = el;
+    }
+    s->head = el;
+    return el;
+}
+
+set* new_set(int id) {
+    set* s = malloc(sizeof(set));
+    s->id = id;
+    s->prev = s->next = NULL;
+    s->head = NULL;
+    s->bucket = NULL;
+    return s;
+}
+
+parent* new_parent(element* el) {
+    parent* p = malloc(sizeof(parent));
+    p->pos = el;
+    p->next = NULL;
+    return p;
+}
+
+void insert_parent(parent** parents, element* el) {
+    int id = el->id;
+    parent* p  = new_parent(el);
+    if (parents[id]) {
+        p->next = parents[id];
+    }
+    parents[id] = p;
+}
+
+bucket* new_bucket(set* s, int size) {
+    bucket* b = malloc(sizeof(bucket));
+    b->size = size;
+    b->prev = b->next = NULL;
+    b->head = s;
+    s->bucket = b;
+    s->prev = s->next = NULL;
+    return b;
+}
+
+void insert_set(set* s, bucket* b) {
+    s->next = b->head;
+    s->prev = NULL;
+    s->bucket = b;
+    b->head->prev = s;
+    b->head = s;
+}
+
+void remove_bucket(bucket* b) {
+    if (b->prev) {
+        b->prev->next = b->next;
+    }
+    if (b->next) {
+        b->next->prev = b->prev;
+    }
+    free(b);
+}
+
+void detach_set(set* s) {
+    if (s->next) {
+        s->next->prev = s->prev;
+    }
+    if (s->prev) {
+        s->prev->next = s->next;
+    } else {
+        s->bucket->head = s->next;
+    }
+    s->prev = s->next = NULL;
+    s->bucket = NULL;
+}
+
+void attach_set(set* s, int size, bucket* b) {
+    if (b->size == size) {
+        insert_set(s, b);
+    } else {
+        bucket* nb =  new_bucket(s, size);
+        nb->prev = b;
+        nb->next = b->next;
+        nb->prev->next = nb;
+        if (nb->next) {
+            nb->next->prev = nb;
+        }
+    }
+}
+
+void demote(set* s) {
+    bucket* b = s->bucket;
+    detach_set(s);
+    int size = b->size - 1;
+    if (size == 0) {
+        free(s);
+    } else if (!b->prev) {
+        bucket* nb = new_bucket(s, size);
+        nb->next = b;
+        b->prev = nb;
+    } else {
+        attach_set(s, size, b->prev);
+    }
+    if (!b->head) {
+        remove_bucket(b);
+    }
+}
+
+void remove_element(element* el) {
+    if (el->next) {
+        el->next->prev = el->prev;
+    }
+    if (el->prev) {
+        el->prev->next = el->next;
+    } else {
+        el->set->head = el->next;
+    }
+    demote(el->set);
+    free(el);
+}
+
+void remove_parents(element* el, parent** parents) {
+    parent* current = parents[el->id];
+    parent* temp;
+    while (current) {
+        temp = current;
+        if (current->pos != el) {
+            remove_element(current->pos);
+        }
+        current = current->next; 
+        free(temp);
+    }
+
+}
+
+void greedy(bucket* head, parent** parents) {
+    bucket* b = head;
+    element* current = b->head->head;
+    printf("%d\n", current->set->id);
+    element* temp;
+    while (1) {
+        temp = current;
+        remove_parents(current, parents);
+        if (current->next) {
+            current = current->next;
+        } else if (current->set->next) {
+            current = current->set->next->head;
+            printf("%d\n", current->set->id);
+        } else if (current->set->bucket->prev) {
+            current = current->set->bucket->prev->head->head;
+            printf("%d\n", current->set->id);
+        } else {
+            break;
+        }
+    }
+}