From 661d3ed0307551f5471d9335397ee9608f48daaa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aur=C3=A9lien=20Ooms?= <aurelien.ooms@gmail.com>
Date: Thu, 24 Sep 2020 13:55:24 +0200
Subject: [PATCH] :sparkles: feat: Improve API for maximum cardinality
 matching.

---
 README.md                      |  9 ++++++++-
 src/addDefaultWeight.js        |  2 ++
 src/cardinality/opt/general.js |  3 ++-
 src/index.js                   |  3 ++-
 test/src/cardinality.js        | 14 ++++++++++++--
 test/src/readme.js             | 19 ++++++++++++++++++-
 6 files changed, 44 insertions(+), 6 deletions(-)
 create mode 100644 src/addDefaultWeight.js

diff --git a/README.md b/README.md
index ca6ab27..ff7149f 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,14 @@ See [docs](https://aureooms.github.io/js-maximum-matching/index.html).
 import maximumMatching, {iter} from '@aureooms/js-maximum-matching';
 const edges = [[1, 2, 10], [2, 3, 11]] ;
 const matching = maximumMatching(edges) ; // [-1, -1, 3, 2]
-iter(matching); // [ [2, 3] ]
+[...iter(matching)]; // [ [2, 3] ]
+
+import maximumCardinalityMatching from '@aureooms/js-maximum-matching/cardinality';
+for (const edge of iter(maximumCardinalityMatching([[1, 2], [2, 3], [3, 4]]))) {
+	console.log(edge);
+}
+// [1,2]
+// [3,4]
 ```
 
 [![License](https://img.shields.io/github/license/aureooms/js-maximum-matching.svg)](https://raw.githubusercontent.com/aureooms/js-maximum-matching/master/LICENSE)
diff --git a/src/addDefaultWeight.js b/src/addDefaultWeight.js
new file mode 100644
index 0000000..9f4f36c
--- /dev/null
+++ b/src/addDefaultWeight.js
@@ -0,0 +1,2 @@
+const addDefaultWeight = (edges) => edges.map(([u, v, w]) => [u, v, w || 1]);
+export default addDefaultWeight;
diff --git a/src/cardinality/opt/general.js b/src/cardinality/opt/general.js
index abb54a6..0d39c92 100644
--- a/src/cardinality/opt/general.js
+++ b/src/cardinality/opt/general.js
@@ -1,5 +1,6 @@
 import blossomNoChecks from '../../core/blossomNoChecks';
+import addDefaultWeight from '../../addDefaultWeight';
 
-const general = (edges) => blossomNoChecks(edges, true);
+const general = (edges) => blossomNoChecks(addDefaultWeight(edges), true);
 
 export default general;
diff --git a/src/index.js b/src/index.js
index f0dde99..4a3e251 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,7 +2,8 @@ import cardinality from './cardinality';
 import core from './core';
 import weight from './weight';
 import iter from './iter';
+import addDefaultWeight from './addDefaultWeight';
 
 export default weight;
 
-export {cardinality, core, weight, iter};
+export {cardinality, core, weight, iter, addDefaultWeight};
diff --git a/test/src/cardinality.js b/test/src/cardinality.js
index d370ae4..89fcd15 100644
--- a/test/src/cardinality.js
+++ b/test/src/cardinality.js
@@ -2,6 +2,7 @@ import test from 'ava';
 import {enumerate} from '@aureooms/js-itertools';
 
 import maximumCardinalityMatching from '../../src/cardinality';
+import {addDefaultWeight} from '../../src';
 import blossom from '../../src/core/blossom';
 
 const macro = (t, algorithm, edges, expected) => {
@@ -16,6 +17,15 @@ macro.title = (title, algorithm, edges, expected) =>
 	`${algorithm.name}(${JSON.stringify(edges)}) = ${JSON.stringify(expected)}`;
 
 const tests = {
+	withoutWeights: {
+		edges: [
+			[1, 2],
+			[2, 3],
+			[3, 4]
+		],
+		expected: [-1, 2, 1, 4, 3]
+	},
+
 	test14_maxcard: {
 		edges: [
 			[1, 2, 5],
@@ -42,8 +52,8 @@ const bdflt = blossom();
 
 const algorithms = [
 	maximumCardinalityMatching,
-	(edges) => btt(edges, true),
-	(edges) => bdflt(edges, true)
+	(edges) => btt(addDefaultWeight(edges), true),
+	(edges) => bdflt(addDefaultWeight(edges), true)
 ];
 
 for (const [i, algorithm] of enumerate(algorithms))
diff --git a/test/src/readme.js b/test/src/readme.js
index e7aafb7..81a9e51 100644
--- a/test/src/readme.js
+++ b/test/src/readme.js
@@ -1,8 +1,9 @@
 import test from 'ava';
 
 import maximumMatching, {iter} from '../../src';
+import maximumCardinalityMatching from '../../src/cardinality';
 
-test('README', (t) => {
+test('weight', (t) => {
 	const edges = [
 		[1, 2, 10],
 		[2, 3, 11]
@@ -11,3 +12,19 @@ test('README', (t) => {
 	t.deepEqual([-1, -1, 3, 2], matching);
 	t.deepEqual([[2, 3]], [...iter(matching)]);
 });
+
+test('cardinality', (t) => {
+	const edges = [
+		[1, 2],
+		[2, 3],
+		[3, 4]
+	];
+	const result = [...iter(maximumCardinalityMatching(edges))];
+	t.deepEqual(
+		[
+			[1, 2],
+			[3, 4]
+		],
+		result
+	);
+});