feat: add js solutions to lc problems: No.219,3163 (#3716)

Author: 07subhadip

solution/0200-0299/0219.Contains Duplicate II/Solution.js

@@ -0,0 +1,15 @@
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {boolean}
+ */
+var containsNearbyDuplicate = function(nums, k) {
+    const d = new Map();
+    for (let i = 0; i < nums.length; ++i) {
+        if (d.has(nums[i]) && i - d.get(nums[i]) <= k) {
+            return true;
+        }
+        d.set(nums[i], i);
+    }
+    return false;
+};

solution/3100-3199/3163.String Compression III/Solution.js

@@ -0,0 +1,22 @@
+/**
+ * @param {string} word
+ * @return {string}
+ */
+var compressedString = function(word) {
+    const ans = [];
+    const n = word.length;
+    for (let i = 0; i < n;) {
+        let j = i + 1;
+        while (j < n && word[j] === word[i]) {
+            ++j;
+        }
+        let k = j - i;
+        while (k) {
+            const x = Math.min(k, 9);
+            ans.push(x + word[i]);
+            k -= x;
+        }
+        i = j;
+    }
+    return ans.join('');
+};