From d5f21d534198069fee0dd4a90397d1322d435179 Mon Sep 17 00:00:00 2001
From: eat to 160 pounds <2915390277@qq.com>
Date: Sun, 24 Apr 2022 21:05:31 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0=E4=BA=86=E4=B8=89=E6=95=B0?=
 =?UTF-8?q?=E4=B9=8B=E5=92=8Cjavascript=E7=89=88=E6=9C=AC?=
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---
 problems/0015.三数之和.md | 70 +++++++++++++----------------------
 1 file changed, 26 insertions(+), 44 deletions(-)

diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md
index bfde6b35..cc184c87 100644
--- a/problems/0015.三数之和.md
+++ b/problems/0015.三数之和.md
@@ -313,54 +313,36 @@ func threeSum(nums []int)[][]int{
 javaScript: 
 
 ```js
-/**
- * @param {number[]} nums
- * @return {number[][]}
- */
-
-// 循环内不考虑去重 
 var threeSum = function(nums) {
-    const len = nums.length;
-    if(len < 3) return [];
-    nums.sort((a, b) => a - b);
-    const resSet = new Set();
-    for(let i = 0; i < len - 2; i++) {
-        if(nums[i] > 0) break;
-        let l = i + 1, r = len - 1;
+    const res = [], len = nums.length
+    // 将数组排序
+    nums.sort((a, b) => a - b)
+    for (let i = 0; i < len; i++) {
+        let l = i + 1, r = len - 1, iNum = nums[i]
+        // 数组排过序，如果第一个数大于0直接返回res
+        if (iNum > 0) return res
+        // 去重
+        if (iNum == nums[i - 1]) continue
         while(l < r) {
-            const sum = nums[i] + nums[l] + nums[r];
-            if(sum < 0) { l++; continue };
-            if(sum > 0) { r--; continue };
-            resSet.add(`${nums[i]},${nums[l]},${nums[r]}`);
-            l++;
-            r--;
+            let lNum = nums[l], rNum = nums[r], threeSum = iNum + lNum + rNum
+            // 三数之和小于0，则左指针向右移动
+            if (threeSum < 0) l++ 
+            else if (threeSum > 0) r--
+            else {
+                res.push([iNum, lNum, rNum])
+                // 去重
+                while(l < r && nums[l] == nums[l + 1]){
+                    l++
+                }
+                while(l < r && nums[r] == nums[r - 1]) {
+                    r--
+                }
+                l++
+                r--
+            }
         }
     }
-    return Array.from(resSet).map(i => i.split(","));
-};
-
-// 去重优化
-var threeSum = function(nums) {
-    const len = nums.length;
-    if(len < 3) return [];
-    nums.sort((a, b) => a - b);
-    const res = [];
-    for(let i = 0; i < len - 2; i++) {
-        if(nums[i] > 0) break;
-        // a去重
-        if(i > 0 && nums[i] === nums[i - 1]) continue;
-        let l = i + 1, r = len - 1;
-        while(l < r) {
-            const sum = nums[i] + nums[l] + nums[r];
-            if(sum < 0) { l++; continue };
-            if(sum > 0) { r--; continue };
-            res.push([nums[i], nums[l], nums[r]])
-            // b c 去重 
-            while(l < r && nums[l] === nums[++l]);
-            while(l < r && nums[r] === nums[--r]);
-        }
-    }
-    return res;
+    return res
 };
 ```
 TypeScript: