From e0c6492d6e141d8ff20a1bd2a2cc4d0337b88286 Mon Sep 17 00:00:00 2001
From: Steve2020 <841532108@qq.com>
Date: Thu, 20 Jan 2022 14:56:16 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880028.=E5=AE=9E?=
 =?UTF-8?q?=E7=8E=B0strStr.md=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescrip?=
 =?UTF-8?q?t=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0028.实现strStr.md | 77 +++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/problems/0028.实现strStr.md b/problems/0028.实现strStr.md
index f0b56719..5f1fa137 100644
--- a/problems/0028.实现strStr.md
+++ b/problems/0028.实现strStr.md
@@ -929,6 +929,83 @@ var strStr = function (haystack, needle) {
 };
 ```
 
+TypeScript版本：
+
+> 前缀表统一减一
+
+```typescript
+function strStr(haystack: string, needle: string): number {
+    function getNext(str: string): number[] {
+        let next: number[] = [];
+        let j: number = -1;
+        next[0] = j;
+        for (let i = 1, length = str.length; i < length; i++) {
+            while (j >= 0 && str[i] !== str[j + 1]) {
+                j = next[j];
+            }
+            if (str[i] === str[j + 1]) {
+                j++;
+            }
+            next[i] = j;
+        }
+        return next;
+    }
+    if (needle.length === 0) return 0;
+    let next: number[] = getNext(needle);
+    let j: number = -1;
+    for (let i = 0, length = haystack.length; i < length; i++) {
+        while (j >= 0 && haystack[i] !== needle[j + 1]) {
+            j = next[j];
+        }
+        if (haystack[i] === needle[j + 1]) {
+            if (j === needle.length - 2) {
+                return i - j - 1;
+            }
+            j++;
+        }
+    }
+    return -1;
+};
+```
+
+> 前缀表不减一
+
+```typescript
+// 不减一版本
+function strStr(haystack: string, needle: string): number {
+    function getNext(str: string): number[] {
+        let next: number[] = [];
+        let j: number = 0;
+        next[0] = j;
+        for (let i = 1, length = str.length; i < length; i++) {
+            while (j > 0 && str[i] !== str[j]) {
+                j = next[j - 1];
+            }
+            if (str[i] === str[j]) {
+                j++;
+            }
+            next[i] = j;
+        }
+        return next;
+    }
+    if (needle.length === 0) return 0;
+    let next: number[] = getNext(needle);
+    let j: number = 0;
+    for (let i = 0, length = haystack.length; i < length; i++) {
+        while (j > 0 && haystack[i] !== needle[j]) {
+            j = next[j - 1];
+        }
+        if (haystack[i] === needle[j]) {
+            if (j === needle.length - 1) {
+                return i - j;
+            }
+            j++;
+        }
+    }
+    return -1;
+}
+```
+
 Swift 版本
 
 > 前缀表统一减一