feat(LeetCode): add solutions

LeetCode/reverse-string.ts

@@ -0,0 +1,14 @@
+/**
+ Do not return anything, modify s in-place instead.
+ */
+function reverseString(s: string[]): void {
+  let l = 0;
+  let r = s.length - 1;
+
+  while (l < r) {
+    [s[l], s[r]] = [s[r], s[l]];
+    l++, r--;
+  }
+}
+
+reverseString(['h', 'e', 'l', 'l', 'o']); // [ 'o', 'l', 'l', 'e', 'h' ]

LeetCode/reverse-vowels-of-a-string.ts

@@ -0,0 +1,19 @@
+function reverseVowels(s: string): string {
+  const vowels = 'aeiouAEIOU';
+  let res = s.split('');
+
+  let l = 0;
+  let r = s.length - 1;
+
+  while (l < r) {
+    if (!vowels.includes(res[l])) l++;
+    if (!vowels.includes(res[r])) r--;
+
+    if (!vowels.includes(res[l]) || !vowels.includes(res[r])) continue;
+
+    [res[l], res[r]] = [res[r], res[l]];
+    l++, r--;
+  }
+
+  return res.join('');
+}

LeetCode/third-maximum-number.ts

@@ -0,0 +1,11 @@
+function thirdMax(nums: number[]): number {
+  const s = [...new Set<number>(nums)].sort((a, b) => b - a);
+
+  // return s.length >= 3 ? s[2] : s[0];
+  return s[2] ?? s[0]; // same above
+}
+
+console.log(thirdMax([3, 2, 1])); // 1
+console.log(thirdMax([1, 2])); // 2
+console.log(thirdMax([2, 2, 3, 1])); // 1
+console.log(thirdMax([1, 1, 2])); // 2