Add js solution to leetcode problem: no.259

Author: tchx626

solution/0200-0299/0259.3Sum Smaller/README.md

@@ -83,6 +83,37 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var threeSumSmaller = function (nums, target) {
+    let len = nums.length;
+    if (len < 3) return 0;
+    nums.sort((a, b) => a - b)
+    let res = 0;
+    for (let i = 0; i < len - 2; i++) {
+        let left = i + 1, right = len - 1;
+        if (nums[i] + nums[left] + nums[i + 2] >= target) break;
+        while (left < right) {
+            if (nums[i] + nums[left] + nums[right] < target) {
+                res += (right - left);
+                left++;
+                continue;
+            } else {
+                right--;
+                continue;
+            }
+        }
+    }
+    return res;
+};
+```
+
 ### **...**
 
 ```

solution/0200-0299/0259.3Sum Smaller/README_EN.md

@@ -99,6 +99,37 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var threeSumSmaller = function (nums, target) {
+    let len = nums.length;
+    if (len < 3) return 0;
+    nums.sort((a, b) => a - b)
+    let res = 0;
+    for (let i = 0; i < len - 2; i++) {
+        let left = i + 1, right = len - 1;
+        if (nums[i] + nums[left] + nums[i + 2] >= target) break;
+        while (left < right) {
+            if (nums[i] + nums[left] + nums[right] < target) {
+                res += (right - left);
+                left++;
+                continue;
+            } else {
+                right--;
+                continue;
+            }
+        }
+    }
+    return res;
+};
+```
+
 ### **...**
 
 ```

solution/0200-0299/0259.3Sum Smaller/Solution.js

@@ -0,0 +1,26 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var threeSumSmaller = function (nums, target) {
+    let len = nums.length;
+    if (len < 3) return 0;
+    nums.sort((a, b) => a - b)
+    let res = 0;
+    for (let i = 0; i < len - 2; i++) {
+        let left = i + 1, right = len - 1;
+        if (nums[i] + nums[left] + nums[i + 2] >= target) break;
+        while (left < right) {
+            if (nums[i] + nums[left] + nums[right] < target) {
+                res += (right - left);
+                left++;
+                continue;
+            } else {
+                right--;
+                continue;
+            }
+        }
+    }
+    return res;
+};