Data commit

Task/Set-consolidation/C/set-consolidation-1.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+
+#define s(x) (1U << ((x) - 'A'))
+
+typedef unsigned int bitset;
+
+int consolidate(bitset *x, int len)
+{
+	int i, j;
+	for (i = len - 2; i >= 0; i--)
+		for (j = len - 1; j > i; j--)
+			if (x[i] & x[j])
+				x[i] |= x[j], x[j] = x[--len];
+	return len;
+}
+
+void show_sets(bitset *x, int len)
+{
+	bitset b;
+	while(len--) {
+		for (b = 'A'; b <= 'Z'; b++)
+			if (x[len] & s(b)) printf("%c ", b);
+		putchar('\n');
+	}
+}
+
+int main(void)
+{
+	bitset x[] = { s('A') | s('B'), s('C') | s('D'), s('B') | s('D'),
+			s('F') | s('G') | s('H'), s('H') | s('I') | s('K') };
+
+	int len = sizeof(x) / sizeof(x[0]);
+
+	puts("Before:"); show_sets(x, len);
+	puts("\nAfter:"); show_sets(x, consolidate(x, len));
+	return 0;
+}

Task/Set-consolidation/C/set-consolidation-2.c

@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct edge { int to; struct edge *next; };
+struct node { int group; struct edge *e; };
+
+int **consolidate(int **x)
+{
+#	define alloc(v, size) v = calloc(size, sizeof(v[0]));
+	int group, n_groups, n_nodes;
+	int n_edges = 0;
+	struct edge *edges, *ep;
+	struct node *nodes;
+	int pos, *stack, **ret;
+
+	void add_edge(int a, int b) {
+		ep->to = b;
+		ep->next = nodes[a].e;
+		nodes[a].e = ep;
+		ep++;
+	}
+
+	void traverse(int a) {
+		if (nodes[a].group) return;
+
+		nodes[a].group = group;
+		stack[pos++] = a;
+
+		for (struct edge *e = nodes[a].e; e; e = e->next)
+			traverse(e->to);
+	}
+
+	n_groups = n_nodes = 0;
+	for (int i = 0; x[i]; i++, n_groups++)
+		for (int j = 0; x[i][j]; j++) {
+			n_edges ++;
+			if (x[i][j] >= n_nodes)
+				n_nodes = x[i][j] + 1;
+		}
+
+	alloc(ret, n_nodes);
+	alloc(nodes, n_nodes);
+	alloc(stack, n_nodes);
+	ep = alloc(edges, n_edges);
+
+	for (int i = 0; x[i]; i++)
+		for (int *s = x[i], j = 0; s[j]; j++)
+			add_edge(s[j], s[j + 1] ? s[j + 1] : s[0]);
+
+	group = 0;
+	for (int i = 1; i < n_nodes; i++) {
+		if (nodes[i].group) continue;
+
+		group++, pos = 0;
+		traverse(i);
+
+		stack[pos++] = 0;
+		ret[group - 1] = malloc(sizeof(int) * pos);
+		memcpy(ret[group - 1], stack, sizeof(int) * pos);
+	}
+
+	free(edges);
+	free(stack);
+	free(nodes);
+
+	// caller is responsible for freeing ret
+	return realloc(ret, sizeof(ret[0]) * (1 + group));
+#	undef alloc
+}
+
+void show_sets(int **x)
+{
+	for (int i = 0; x[i]; i++) {
+		printf("%d: ", i);
+		for (int j = 0; x[i][j]; j++)
+			printf(" %d", x[i][j]);
+		putchar('\n');
+	}
+}
+
+int main(void)
+{
+	int *x[] = {
+		(int[]) {1, 2, 0},	// 0: end of set
+		(int[]) {3, 4, 0},
+		(int[]) {3, 1, 0},
+		(int[]) {0},		// empty set
+		(int[]) {5, 6, 0},
+		(int[]) {7, 6, 0},
+		(int[]) {3, 9, 10, 0},
+		0			// 0: end of sets
+	};
+
+	puts("input:");
+	show_sets(x);
+
+	puts("components:");
+	show_sets(consolidate(x));
+
+	return 0;
+}