Data commit

Task/Last-letter-first-letter/JavaScript/last-letter-first-letter.js

@@ -0,0 +1,90 @@
+/**
+ * Find the letter the word ends on
+ * @param {string} word
+ * @returns {string}
+ */
+const endsWith = word => word[word.length - 1];
+
+/**
+ * Remove the used elements from the candidate elements
+ * @param {Array<string>} words Candidate words
+ * @param {Array<string>} used Used words
+ * @returns {*}
+ */
+const getCandidates = (words, used) => words.filter(e => !used.includes(e));
+
+/**
+ * Build a map of letters to words that start with that letter
+ * @param {Array<string>} words
+ * @returns {Map<string, Array<string>>}
+ */
+const buildLookup = words => {
+  const lookup = new Map();
+  words.forEach(e => {
+    const start = e[0];
+    lookup.set(start, [...(lookup.get(start) || []), e]);
+  });
+  return lookup;
+};
+
+
+/**
+ * Main function
+ * @param {Array<string>} names
+ */
+const findPaths = names => {
+  const t0 = process.hrtime();
+  console.log('Checking:', names.length, 'names');
+  const lookup = buildLookup(names);
+
+  let maxNum = 0;
+  let maxPaths = [];
+
+  const parseResult = arr => {
+    if (typeof arr[0] === 'object') {
+      arr.forEach(el => parseResult(el))
+    } else {
+      if (arr.length > maxNum) {
+        maxNum = arr.length;
+        maxPaths = [arr];
+      }
+      if (arr.length === maxNum) {
+        maxPaths.push(arr)
+      }
+    }
+  };
+
+  const searchWords = (word, res) => {
+    const cs = getCandidates(lookup.get(endsWith(word)) || [], res);
+    return cs.length ? cs.map(e => searchWords(e, [...res, e])) : res;
+  };
+
+  names.forEach(word => {
+    const res = searchWords(word, [word]);
+    parseResult(res);
+  });
+
+  const t1 = process.hrtime(t0);
+  console.info('Execution time (hr): %ds %dms', t1[0], t1[1] / 1000000);
+  console.log('Max Path:', maxNum);
+  console.log('Matching Paths:', maxPaths.length);
+  console.log('Example Path:', maxPaths[0]);
+
+};
+
+const pokimon = ["audino", "bagon", "baltoy", "banette",
+  "bidoof", "braviary", "bronzor", "carracosta", "charmeleon",
+  "cresselia", "croagunk", "darmanitan", "deino", "emboar",
+  "emolga", "exeggcute", "gabite", "girafarig", "gulpin",
+  "haxorus", "heatmor", "heatran", "ivysaur", "jellicent",
+  "jumpluff", "kangaskhan", "kricketune", "landorus", "ledyba",
+  "loudred", "lumineon", "lunatone", "machamp", "magnezone",
+  "mamoswine", "nosepass", "petilil", "pidgeotto", "pikachu",
+  "pinsir", "poliwrath", "poochyena", "porygon2", "porygonz",
+  "registeel", "relicanth", "remoraid", "rufflet", "sableye",
+  "scolipede", "scrafty", "seaking", "sealeo", "silcoon",
+  "simisear", "snivy", "snorlax", "spoink", "starly", "tirtouga",
+  "trapinch", "treecko", "tyrogue", "vigoroth", "vulpix",
+  "wailord", "wartortle", "whismur", "wingull", "yamask"];
+
+findPaths(pokimon);