Add pset3, took 15 + 32 = 47 mins

semester3/pset3/7-2-Binomial-Queue-TakeTwo.c

@@ -0,0 +1,189 @@
+// 15:10 - 15:42 - 32min
+#include <stdio.h>
+#include <stdlib.h>
+#define MAX 100
+
+typedef struct node {
+  int val, degree;
+  struct node *child, *sibling;
+} node;
+
+typedef struct list {
+  node **arr;
+  int size;
+} list;
+
+node *newNode(int val) {
+  node *n = malloc(sizeof(node));
+  n->val = val;
+  n->degree = 0;
+  n->child = NULL;
+  n->sibling = NULL;
+
+  return n;
+}
+
+list *newList(int capacity) {
+  list *li = malloc(sizeof(list));
+
+  li->arr = malloc(sizeof(node *) * capacity);
+  li->size = 0;
+
+  return li;
+}
+
+void pushBack(list *li, node *n) { li->arr[li->size++] = n; }
+
+list *erase(list *li, int loc) {
+  for (int i = loc, size = li->size; i < size - 1; i++) {
+    li->arr[i] = li->arr[i + 1];
+  }
+  li->size--;
+  return li;
+}
+
+list *unionList(list *l, list *r) {
+  int i = 0, j = 0;
+  list *li = newList(MAX);
+
+  while (i < l->size && j < r->size) {
+    if (l->arr[i]->degree < r->arr[j]->degree) {
+      pushBack(li, l->arr[i++]);
+    } else {
+      pushBack(li, r->arr[j++]);
+    }
+  }
+
+  while (i < l->size) {
+    pushBack(li, l->arr[i++]);
+  }
+  while (j < r->size) {
+    pushBack(li, r->arr[j++]);
+  }
+
+  return li;
+}
+
+void swapNode(node *l, node *r) {
+  node tmp = *l;
+  *l = *r;
+  *r = tmp;
+}
+
+node *merge(node *l, node *r) {
+  // remember, smaller one goes up
+  if (l->val > r->val) {
+    swapNode(l, r);
+  }
+  r->sibling = l->child;
+  l->child = r;
+
+  l->degree++;
+
+  return l;
+}
+
+list *adjust(list *li) {
+  if (li->size == 1) {
+    return li;
+  }
+  int i = 0, j = 0, k = 0;
+  if (li->size == 2) {
+    j = 1;
+    k = li->size;
+  } else {
+    j = 1;
+    k = 2;
+  }
+
+  while (i < li->size) {
+    if (j == li->size) {
+      i++;
+    } else if (li->arr[i]->degree < li->arr[j]->degree) {
+      i++;
+      j++;
+      if (k < li->size) {
+        k++;
+      }
+    } else if (k < li->size && li->arr[i]->degree == li->arr[j]->degree &&
+               li->arr[i]->degree == li->arr[k]->degree) {
+      i++;
+      j++;
+      k++;
+    } else if (li->arr[i]->degree == li->arr[j]->degree) {
+      li->arr[i] = merge(li->arr[i], li->arr[j]);
+      erase(li, j);
+    }
+  }
+  return li;
+}
+
+list *insert(list *li, int val) {
+  node *n = newNode(val);
+  list *tmp = newList(MAX);
+  pushBack(tmp, n);
+
+  tmp = unionList(li, tmp);
+  return adjust(tmp);
+}
+
+int getDigits(int i) {
+  int count = 0;
+  while (i) {
+    i /= 10;
+    count++;
+  }
+
+  return count;
+}
+
+void printLevel(node *n, int level) {
+  if (n) {
+    printLevel(n->sibling, level);
+    if (level == 1) {
+      printf("%d,", n->val);
+    } else {
+      printLevel(n->child, level - 1);
+    }
+  }
+}
+
+void printHeap(node *n) {
+  int level = 0;
+  for (node *ptr = n; ptr != NULL; ptr = ptr->child) {
+    printLevel(n, ++level);
+  }
+}
+
+void printTree(list *li, int k) {
+  int present = 0;
+  for (int i = 0, size = li->size; i < size; i++) {
+    if (li->arr[i]->degree == k) {
+      printHeap(li->arr[i]);
+      present = 1;
+    }
+  }
+
+  if (!present) {
+    printf("0,\n");
+  }
+}
+
+int main(void) {
+  char buf[MAX];
+  fgets(buf, MAX, stdin);
+  list *li = newList(MAX);
+
+  int tmp;
+  int offset = 0;
+  while (sscanf(buf + offset, "%d,", &tmp) != EOF) {
+    li = insert(li, tmp);         // remember li =
+    offset += getDigits(tmp) + 1; // remember to + 1
+  }
+
+  int k;
+  scanf("%d", &k);
+  printTree(li, k);
+
+  return 0;
+}

semester3/pset3/7-2-Binomial-Queue.c

@@ -79,6 +79,7 @@ Node *merge(Node *l, Node *r) {
     swapNode(l, r);
   }
 
+  // sub-node might have a sibling, but head node doesn't have one.
   r->parent = l;
   r->sibling = l->child;
 
@@ -105,7 +106,7 @@ list *adjust(list *l) {
 
   // can't use i != size here, since the list will shrink.
   while (i < l->size) {
-    // only one element remains
+    // only one element remains, if j > size, then i == size
     if (j == l->size) {
       i++;
     } else if (l->arr[i]->degree < l->arr[j]->degree) {
@@ -116,15 +117,14 @@ list *adjust(list *l) {
       }
     } else if (k < l->size && l->arr[i]->degree == l->arr[j]->degree &&
                l->arr[i]->degree == l->arr[k]->degree) {
+      // at most 3 same degrees, because of binary operations
       i++;
       j++;
       k++;
     } else if (l->arr[i]->degree == l->arr[j]->degree) {
       l->arr[i] = merge(l->arr[i], l->arr[j]);
       erase(l, j);
-      if (k < l->size) {
-        k++;
-      }
+      // doesn't have to move k
     }
   }