tasks a-s

Task/Same-Fringe/C/same-fringe.c

@@ -0,0 +1,121 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ucontext.h>
+
+typedef struct {
+	ucontext_t caller, callee;
+	char stack[8192];
+	void *in, *out;
+} co_t;
+
+co_t * co_new(void(*f)(), void *data)
+{
+	co_t * c = malloc(sizeof(*c));
+	getcontext(&c->callee);
+	c->in = data;
+
+	c->callee.uc_stack.ss_sp = c->stack;
+	c->callee.uc_stack.ss_size = sizeof(c->stack);
+	c->callee.uc_link = &c->caller;
+	makecontext(&c->callee, f, 1, (int)c);
+
+	return c;
+}
+
+void co_del(co_t *c)
+{
+	free(c);
+}
+
+inline void
+co_yield(co_t *c, void *data)
+{
+	c->out = data;
+	swapcontext(&c->callee, &c->caller);
+}
+
+inline void *
+co_collect(co_t *c)
+{
+	c->out = 0;
+	swapcontext(&c->caller, &c->callee);
+	return c->out;
+}
+
+// end of coroutine stuff
+
+typedef struct node node;
+struct node {
+	int v;
+	node *left, *right;
+};
+
+node *newnode(int v)
+{
+	node *n = malloc(sizeof(node));
+	n->left = n->right = 0;
+	n->v = v;
+	return n;
+}
+
+void tree_insert(node **root, node *n)
+{
+	while (*root) root = ((*root)->v > n->v)
+				? &(*root)->left
+				: &(*root)->right;
+	*root = n;
+}
+
+void tree_trav(int x)
+{
+	co_t *c = (co_t *) x;
+
+	void trav(node *root) {
+		if (!root) return;
+		trav(root->left);
+		co_yield(c, root);
+		trav(root->right);
+	}
+
+	trav(c->in);
+}
+
+int tree_eq(node *t1, node *t2)
+{
+	co_t *c1 = co_new(tree_trav, t1);
+	co_t *c2 = co_new(tree_trav, t2);
+
+	node *p = 0, *q = 0;
+	do {
+		p = co_collect(c1);
+		q = co_collect(c2);
+	} while (p && q && (p->v == q->v));
+
+	co_del(c1);
+	co_del(c2);
+	return !p && !q;
+}
+
+int main()
+{
+	int x[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1 };
+	int y[] = { 2, 5, 7, 1, 9, 0, 6, 4, 8, 3, -1 };
+	int z[] = { 0, 1, 2, 3, 4, 5, 6, 8, 9, -1 };
+
+	node *t1 = 0, *t2 = 0, *t3 = 0;
+
+	void mktree(int *buf, node **root) {
+		int i;
+		for (i = 0; buf[i] >= 0; i++)
+			tree_insert(root, newnode(buf[i]));
+	}
+
+	mktree(x, &t1); // ordered binary tree, result of traversing
+	mktree(y, &t2); // should be independent of insertion, so t1 == t2
+	mktree(z, &t3);
+
+	printf("t1 == t2: %s\n", tree_eq(t1, t2) ? "yes" : "no");
+	printf("t1 == t3: %s\n", tree_eq(t1, t3) ? "yes" : "no");
+
+	return 0;
+}