From c75b29bc04c71063266cfbcec97c3398e1d3ef98 Mon Sep 17 00:00:00 2001
From: kok-s0s <2694308562@qq.com>
Date: Wed, 28 Jul 2021 23:46:46 +0800
Subject: [PATCH] =?UTF-8?q?=E6=8F=90=E4=BE=9BJavaScript=E7=89=88=E6=9C=AC?=
 =?UTF-8?q?=E7=9A=84=E3=80=8A=E5=AE=9E=E7=8E=B0strStr()=E3=80=8B?=
MIME-Version: 1.0
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---
 problems/0028.实现strStr.md | 86 +++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/problems/0028.实现strStr.md b/problems/0028.实现strStr.md
index 69f8c9d6..fc14a34a 100644
--- a/problems/0028.实现strStr.md
+++ b/problems/0028.实现strStr.md
@@ -808,7 +808,93 @@ func strStr(haystack string, needle string) int {
 }
 ```
 
+JavaScript版本
 
+> 前缀表统一减一
+
+```javascript
+/**
+ * @param {string} haystack
+ * @param {string} needle
+ * @return {number}
+ */
+var strStr = function (haystack, needle) {
+    if (needle.length === 0)
+        return 0;
+
+    const getNext = (needle) => {
+        let next = [];
+        let j = -1;
+        next.push(j);
+
+        for (let i = 1; i < needle.length; ++i) {
+            while (j >= 0 && needle[i] !== needle[j + 1])
+                j = next[j];
+            if (needle[i] === needle[j + 1])
+                j++;
+            next.push(j);
+        }
+
+        return next;
+    }
+
+    let next = getNext(needle);
+    let j = -1;
+    for (let i = 0; i < haystack.length; ++i) {
+        while (j >= 0 && haystack[i] !== needle[j + 1])
+            j = next[j];
+        if (haystack[i] === needle[j + 1])
+            j++;
+        if (j === needle.length - 1)
+            return (i - needle.length + 1);
+    }
+
+    return -1;
+};
+```
+
+> 前缀表统一不减一
+
+```javascript
+/**
+ * @param {string} haystack
+ * @param {string} needle
+ * @return {number}
+ */
+var strStr = function (haystack, needle) {
+    if (needle.length === 0)
+        return 0;
+
+    const getNext = (needle) => {
+        let next = [];
+        let j = 0;
+        next.push(j);
+
+        for (let i = 1; i < needle.length; ++i) {
+            while (j > 0 && needle[i] !== needle[j])
+                j = next[j - 1];
+            if (needle[i] === needle[j])
+                j++;
+            next.push(j);
+        }
+
+        return next;
+    }
+
+    let next = getNext(needle);
+    let j = 0;
+    for (let i = 0; i < haystack.length; ++i) {
+        while (j > 0 && haystack[i] !== needle[j])
+            j = next[j - 1];
+        if (haystack[i] === needle[j])
+            j++;
+        if (j === needle.length)
+            return (i - needle.length + 1);
+    }
+
+    return -1;
+};
+```