X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fpermutation%2F_info;fp=ccan%2Fpermutation%2F_info;h=4998f5db56862c8c42977a4939a8ac3b55d352c9;hb=c3e9a05832ec5362bf108a7f1487aa4dcff96f99;hp=0000000000000000000000000000000000000000;hpb=e8d1e7304feb9318a841ad4a7d5a8773271ab814;p=ccan

diff --git a/ccan/permutation/_info b/ccan/permutation/_info
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+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+/**
+ * permutation - Generate permutations
+ *
+ * This module allows you to generate all permutations of a given
+ * number of elements.  It can also modify a user-supplied array in
+ * place through all those permutations.
+ *
+ * It uses the "plain changes" method, aka the
+ * Steinhaus-Johnson-Trotter algorithm to generate the permtations.
+ * This has some advantages over a naive recursive algorithm:
+ *
+ * - Each permutation is generated from the last by a single swap of
+ *   adjacent elements
+ *
+ * - Constructing each permutation in place from the last takes
+ *   amortized O(1) time.
+ *
+ * License: LGPL (v2.1 or any later version)
+ * Example:
+ *	// Given "1 2 3" outputs 1 2 3 1 3 2 3 1 2 3 2 1 2 3 1 2 1 3
+ *	#include <stdio.h>
+ *	#include <ccan/permutation/permutation.h>
+ *
+ *	int main(int argc, char *argv[])
+ *	{
+ *		int i;
+ *		struct permutation *pi = permutation_new(argc - 1);
+ *
+ *		do {
+ *			for (i = 1; i < argc; i++)
+ *				printf("%s ", argv[i]);
+ *			printf("\n");
+ *		} while (permutation_change_array(pi,
+ *		         &argv[1], sizeof(argv[1])));
+ *		exit(0);
+ *	}
+ */
+int main(int argc, char *argv[])
+{
+	/* Expect exactly one argument */
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/build_assert\n");
+		printf("ccan/mem\n");
+		return 0;
+	}
+
+	if (strcmp(argv[1], "testdepends") == 0) {
+		printf("ccan/array_size\n");
+		return 0;
+	}
+
+	return 1;
+}