Add relative-distance

Author: BNAndras

config.json

@@ -1414,6 +1414,14 @@
           "text_formatting"
         ]
       },
+      {
+        "slug": "relative-distance",
+        "name": "Relative Distance",
+        "uuid": "c72faac5-8d41-404b-8558-759b94ea22ec",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "saddle-points",
         "name": "Saddle Points",

exercises/practice/relative-distance/.docs/instructions.md

@@ -0,0 +1,39 @@
+# Instructions
+
+Your task is to determine the degree of separation between two individuals in a family tree.
+
+- You will be given an input, with all parent names and their children.
+- Each name is unique, a child _can_ have one or two parents.
+- The degree of separation is defined as the shortest number of connections from one person to another.
+- If two individuals are not connected, return a value that represents "no known relationship."
+  Please see the test cases for the actual implementation.
+
+## Example
+
+Given the following family tree:
+
+```text
+      ┌──────────┐            ┌──────────┐ ┌───────────┐
+      │  Helena  │            │  Erdős   │ │  Shusaku  │
+      └───┬───┬──┘            └─────┬────┘ └──────┬────┘
+      ┌───┘   └───────┐             └──────┬──────┘
+      ▼               ▼                    ▼
+┌──────────┐     ┌────────┐          ┌──────────┐
+│   Isla   │     │  Tariq │          │   Kevin  │
+└────┬─────┘     └────┬───┘          └──────────┘
+     ▼                ▼
+┌─────────┐      ┌────────┐
+│   Uma   │      │ Morphy │
+└─────────┘      └────────┘
+```
+
+The degree of separation between Tariq and Uma is 3 (Tariq → Helena → Isla → Uma).
+There's no known relationship between Isla and [Kevin][six-bacons], as there is no connection in the given data.
+The degree of separation between Uma and Isla is 1.
+
+```exercism/note
+Isla and Tariq are siblings and have a separation of 1.
+Similarly, this implementation would report a separation of 2 from you to your father's brother.
+```
+
+[six-bacons]: https://en.m.wikipedia.org/wiki/Six_Degrees_of_Kevin_Bacon

exercises/practice/relative-distance/.docs/introduction.md

@@ -0,0 +1,12 @@
+# Introduction
+
+You've been hired to develop **Noble Knots**, the hottest new dating app for nobility!
+With centuries of royal intermarriage, things have gotten… _complicated_.
+To avoid any _oops-we're-twins_ situations, your job is to build a system that checks how closely two people are related.
+
+Noble Knots is inspired by Iceland's "[Islendinga-App][islendiga-app]," which is backed up by a database that traces all known family connections between Icelanders from the time of the settlement of Iceland.
+Your algorithm will determine the **degree of separation** between two individuals in the royal family tree.
+
+Will your app help crown a perfect match?
+
+[islendiga-app]: http://www.islendingaapp.is/information-in-english/

exercises/practice/relative-distance/.gitignore

@@ -0,0 +1,5 @@
+/node_modules
+/bin/configlet
+/bin/configlet.exe
+/package-lock.json
+/yarn.lock

exercises/practice/relative-distance/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "relative-distance.js"
+    ],
+    "test": [
+      "relative-distance.spec.js"
+    ],
+    "example": [
+      ".meta/proof.ci.js"
+    ]
+  },
+  "blurb": "Given a family tree, calculate the degree of separation.",
+  "source": "vaeng",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/2537"
+}

exercises/practice/relative-distance/.meta/proof.ci.js

@@ -0,0 +1,52 @@
+export const degreesOfSeparation = (familyTree, personA, personB) => {
+  const neighbors = new Map();
+
+  for (const [parent, children] of Object.entries(familyTree)) {
+    if (!neighbors.has(parent)) {
+      neighbors.set(parent, new Set());
+    }
+
+    for (const child of children) {
+      if (!neighbors.has(child)) {
+        neighbors.set(child, new Set());
+      }
+
+      neighbors.get(parent).add(child);
+      neighbors.get(child).add(parent);
+    }
+
+    //
+    for (const childA of children) {
+      for (const childB of children) {
+        if (childA !== childB) {
+          neighbors.get(childA).add(childB);
+          neighbors.get(childB).add(childA);
+        }
+      }
+    }
+  }
+
+  if (!neighbors.has(personA) || !neighbors.has(personB)) {
+    return -1;
+  }
+
+  const queue = [[personA, 0]];
+  const visited = new Set([personA]);
+
+  while (queue.length > 0) {
+    const [current, degree] = queue.shift();
+
+    if (current === personB) {
+      return degree;
+    }
+
+    for (const neighbor of neighbors.get(current)) {
+      if (!visited.has(neighbor)) {
+        visited.add(neighbor);
+        queue.push([neighbor, degree + 1]);
+      }
+    }
+  }
+
+  return -1;
+};

exercises/practice/relative-distance/.meta/tests.toml

@@ -0,0 +1,31 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[4a1ded74-5d32-47fb-8ae5-321f51d06b5b]
+description = "Direct parent-child relation"
+
+[30d17269-83e9-4f82-a0d7-8ef9656d8dce]
+description = "Sibling relationship"
+
+[8dffa27d-a8ab-496d-80b3-2f21c77648b5]
+description = "Two degrees of separation, grandchild"
+
+[34e56ec1-d528-4a42-908e-020a4606ee60]
+description = "Unrelated individuals"
+
+[93ffe989-bad2-48c4-878f-3acb1ce2611b]
+description = "Complex graph, cousins"
+
+[2cc2e76b-013a-433c-9486-1dbe29bf06e5]
+description = "Complex graph, no shortcut, far removed nephew"
+
+[46c9fbcb-e464-455f-a718-049ea3c7400a]
+description = "Complex graph, some shortcuts, cross-down and cross-up, cousins several times removed, with unrelated family tree"

exercises/practice/relative-distance/.npmrc

@@ -0,0 +1 @@
+audit=false

exercises/practice/relative-distance/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Exercism
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

exercises/practice/relative-distance/babel.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: [['@exercism/babel-preset-javascript', { corejs: '3.40' }]],
+  plugins: [],
+};