add day-ten

Author: libterty

README.md

@@ -10,3 +10,4 @@
     -   Day 7: [Cousins in Binary Tree](https://github.com/libterty/leetcode-challenge/blob/master/src/may/day-seven/index.ts) :hushed:
     -   Day 8: [check Straight Line](https://github.com/libterty/leetcode-challenge/blob/master/src/may/day-eight/index.ts) :grin:
     -   Day 9: [Is Perfect Square](https://github.com/libterty/leetcode-challenge/blob/master/src/may/day-nine/index.ts) :alien:
+    -   Day 10: [Find Town Judge](https://github.com/libterty/leetcode-challenge/blob/master/src/may/day-ten/index.ts) :alien:

src/may/day-ten/index.ts

@@ -0,0 +1,49 @@
+/**
+ * @param {number} N
+ * @param {number[][]} trust
+ * @return {number}
+ */
+export const findJudge = function (N: number, trust: number[][]): number {
+    // hash table for villager
+    const villagerMap: Set<number> = new Set();
+    // hash table for judge
+    const judgeMap: Map<number, number> = new Map();
+
+    for (let i = 0; i < trust.length; i++) {
+        // current trust
+        const trusted: number = trust[i][1];
+        // current trust counts
+        const trust_count: number = judgeMap.get(trusted);
+        // record village
+        villagerMap.add(trust[i][0]);
+        // Save judge
+        trust_count ? judgeMap.set(trusted, trust_count + 1) : judgeMap.set(trusted, 1);
+    }
+
+    for (let [key, value] of judgeMap) {
+        if (value === N - 1 && !villagerMap.has(key)) {
+            return key;
+        }
+    }
+
+    return !trust.length ? N : -1;
+};
+
+const a = findJudge(3, [
+    [1, 3],
+    [2, 3],
+]);
+const b = findJudge(3, [
+    [1, 3],
+    [2, 3],
+    [3, 1],
+]);
+const c = findJudge(4, [
+    [1, 3],
+    [1, 4],
+    [2, 3],
+    [2, 4],
+    [4, 3],
+]);
+
+console.log('logs', a, b, c);