✨ feat(integerValuesKnapsack): Implement DP on values.

Author: make-github-pseudonymous-again

package.json

@@ -27,6 +27,7 @@
             "transform-remove-console",
             {
               "exclude": [
+                "debug",
                 "log",
                 "error",
                 "warn"
@@ -75,7 +76,9 @@
   "bugs": {
     "url": "https://github.com/aureooms/js-knapsack/issues"
   },
-  "dependencies": {},
+  "dependencies": {
+    "@aureooms/js-itertools": "^4.1.0"
+  },
   "devDependencies": {
     "@babel/cli": "7.11.6",
     "@babel/core": "7.11.6",
@@ -101,7 +104,25 @@
     "lib"
   ],
   "homepage": "https://aureooms.github.io/js-knapsack",
-  "keywords": ["agpl", "algorithms", "complete", "computer", "dynamic", "in", "javascript", "knapsack", "meet", "middle", "np", "polynomial", "programming", "pseudo", "reductions", "science", "the"],
+  "keywords": [
+    "agpl",
+    "algorithms",
+    "complete",
+    "computer",
+    "dynamic",
+    "in",
+    "javascript",
+    "knapsack",
+    "meet",
+    "middle",
+    "np",
+    "polynomial",
+    "programming",
+    "pseudo",
+    "reductions",
+    "science",
+    "the"
+  ],
   "license": "AGPL-3.0",
   "main": "lib/index.js",
   "prettier": {

src/index.js

@@ -1,8 +1,10 @@
-import integerKnapsack from './integerKnapsack';
+import integerValuesKnapsack from './integerValuesKnapsack';
+import integerWeightsKnapsack from './integerWeightsKnapsack';
 
 /* eslint import/no-anonymous-default-export: [2, {"allowObject": true}] */
 export default {
-	integerKnapsack,
+	integerValuesKnapsack,
+	integerWeightsKnapsack,
 };
 
-export {integerKnapsack};
+export {integerValuesKnapsack, integerWeightsKnapsack};

src/integerValuesKnapsack.js

@@ -0,0 +1,34 @@
+import assert from 'assert';
+import {sum} from '@aureooms/js-itertools';
+
+const integerValuesKnapsack = (
+	v,
+	w,
+	n,
+	W,
+	V = sum(v),
+	m = new w.constructor(V + 1).fill(Number(Infinity)),
+) => {
+	assert(v.length === n);
+	assert(w.length === n);
+	assert(Number.isInteger(V) && V >= 0);
+	assert(m.length >= V + 1);
+	m[V] = 0;
+	for (let i = 0; i < n; ++i) {
+		const wi = w[i];
+		const vi = v[i];
+		assert(Number.isInteger(vi) && vi >= 0);
+		const k = V - vi + 1;
+		for (let j = 0; j < k; ++j) {
+			m[j] = Math.min(m[j], m[j + vi] + wi);
+		}
+	}
+
+	for (let j = 0; j < V; ++j) {
+		if (m[j] <= W) return V - j;
+	}
+
+	return 0;
+};
+
+export default integerValuesKnapsack;

src/integerKnapsack.js renamed to src/integerWeightsKnapsack.js

@@ -1,6 +1,12 @@
 import assert from 'assert';
 
-const integerKnapsack = (v, w, n, W, m = new v.constructor(W + 1).fill(0)) => {
+const integerWeightsKnapsack = (
+	v,
+	w,
+	n,
+	W,
+	m = new v.constructor(W + 1).fill(0),
+) => {
 	assert(v.length === n);
 	assert(w.length === n);
 	assert(Number.isInteger(W) && W >= 0);
@@ -18,4 +24,4 @@ const integerKnapsack = (v, w, n, W, m = new v.constructor(W + 1).fill(0)) => {
 	return m[0];
 };
 
-export default integerKnapsack;
+export default integerWeightsKnapsack;

test/src/integerKnapsack.js renamed to test/src/integerValuesKnapsack.js

@@ -1,17 +1,17 @@
 import test from 'ava';
 
-import {integerKnapsack} from '../../src';
+import {integerValuesKnapsack} from '../../src';
 
 const macro = (t, v, w, n, W, expected) => {
 	t.is(n, v.length);
 	t.is(n, w.length);
-	const result = integerKnapsack(v, w, n, W);
+	const result = integerValuesKnapsack(v, w, n, W);
 	t.is(expected, result);
 };
 
 macro.title = (title, v, w, n, W, expected) =>
 	title ||
-	`integerKnapsack(${JSON.stringify(v)}, ${JSON.stringify(
+	`integerValuesKnapsack(${JSON.stringify(v)}, ${JSON.stringify(
 		w,
 	)}, ${n}, ${W}) = ${expected}`;
 

test/src/integerWeightsKnapsack.js

@@ -0,0 +1,36 @@
+import test from 'ava';
+
+import {integerWeightsKnapsack} from '../../src';
+
+const macro = (t, v, w, n, W, expected) => {
+	t.is(n, v.length);
+	t.is(n, w.length);
+	const result = integerWeightsKnapsack(v, w, n, W);
+	t.is(expected, result);
+};
+
+macro.title = (title, v, w, n, W, expected) =>
+	title ||
+	`integerWeightsKnapsack(${JSON.stringify(v)}, ${JSON.stringify(
+		w,
+	)}, ${n}, ${W}) = ${expected}`;
+
+test(
+	'wikipedia 0-1 knapsack example',
+	macro,
+	[505, 352, 458, 220, 354, 414, 498, 545, 473, 543],
+	[23, 26, 20, 18, 32, 27, 29, 26, 30, 27],
+	10,
+	67,
+	1270,
+);
+
+test(
+	'https://www.geeksforgeeks.org/0-1-knapsack-problem-dp-10',
+	macro,
+	[60, 100, 120],
+	[10, 20, 30],
+	3,
+	50,
+	220,
+);

yarn.lock

@@ -2,6 +2,26 @@
 # yarn lockfile v1
 
 
+"@aureooms/js-collections-deque@^4.0.1":
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-collections-deque/-/js-collections-deque-4.0.1.tgz#bd8b827cdb597d061525c380dd704e338c77bd5f"
+  integrity sha512-dktRVLyep0sUKpqgtG/JseA232KMdlu9t9ePq2wHcng1dZ3+63qW2C+FlKXBktrT1dU92DDxIL6PqnV97kHA1Q==
+  dependencies:
+    "@aureooms/js-error" "^4.0.1"
+
+"@aureooms/js-error@^4.0.1":
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-error/-/js-error-4.0.1.tgz#be2740b3f31a337e0828930c9b70d38113b4dd77"
+  integrity sha512-zsgs6wmnRsKljlusewYiBaFBM/hIJp43b7OwE9ybpLEL4wfXjGP17cJTTAY8gpzALVFwEA5/flxIK0I6gJJLHQ==
+
+"@aureooms/js-itertools@^4.1.0":
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-itertools/-/js-itertools-4.1.0.tgz#c731eaee7de0005c6ea41f2f87cca4bdb2d86ca1"
+  integrity sha512-P9TfwQPuXk5T5z6QMMfwLLyzh9QsEu4sGWcBk/P/waWgim/xqr+LDTOHVo7WU4QAty+/5CBX8DuW7MrPVfXt5A==
+  dependencies:
+    "@aureooms/js-collections-deque" "^4.0.1"
+    "@aureooms/js-error" "^4.0.1"
+
 "@babel/cli@7.11.6":
   version "7.11.6"
   resolved "https://registry.yarnpkg.com/@babel/cli/-/cli-7.11.6.tgz#1fcbe61c2a6900c3539c06ee58901141f3558482"