From 79fe7d4cf148d4ae414578ae59c93a272a4fb508 Mon Sep 17 00:00:00 2001
From: donjuanplatinum <donjuan@lecturify.net>
Date: Sun, 21 Jul 2024 08:41:42 -0400
Subject: [PATCH] =?UTF-8?q?feat(=E6=9C=80=E5=A4=A7=E5=AD=90=E4=B8=B2)?=
 =?UTF-8?q?=EF=BC=9Amax=5Fstring?=
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---
 src/lib.rs                  |  3 ++
 src/string/max_substring.rs | 97 +++++++++++++++++++++++++++++++++++++
 src/string/mod.rs           |  2 +
 3 files changed, 102 insertions(+)
 create mode 100644 src/string/max_substring.rs
 create mode 100644 src/string/mod.rs

diff --git a/src/lib.rs b/src/lib.rs
index 0dfd90f..82cafe9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,3 +14,6 @@ pub mod math;
 
 /// Tools
 pub mod tools;
+
+/// String
+pub mod string;
diff --git a/src/string/max_substring.rs b/src/string/max_substring.rs
new file mode 100644
index 0000000..bee03bf
--- /dev/null
+++ b/src/string/max_substring.rs
@@ -0,0 +1,97 @@
+/// 最大子串
+/// 
+/// 返回(起始位置,结束位置,长度)
+/// ```
+/// use algori::string::max_substring;
+/// let a = "abcdefgg";
+/// assert_eq!(max_substring(a),(0,6,7));
+///
+/// ```
+pub fn max_substring(s: &str) -> (usize, usize, usize) {
+    let bytes = s.as_bytes();
+    let mut char_set = [false; 128]; // 一个简单的Table
+
+    let (mut start, mut end, mut max_length) = (0, 0, 0); // 结果
+    let mut current_start = 0; // 当前不重复子串的开始位置
+
+    for i in 0..bytes.len() {
+        // 如果字符已经出现过，则移动起始位置
+        while char_set[bytes[i] as usize] == true {
+            char_set[bytes[current_start] as usize] = false; // 弹出
+            current_start += 1; // 移动起始位置
+        }
+
+        // 标记当前字符为已出现
+        char_set[bytes[i] as usize] = true;
+
+        // 更新最大长度和结束位置
+        if i - current_start + 1 > max_length {
+            max_length = i - current_start + 1;
+            start = current_start; // 更新起始位置
+            end = i; // 更新结束位置
+        }
+    }
+
+    // 返回起始位置、结束位置和最大长度
+    return (start, end, max_length);
+}
+
+#[cfg(test)]
+mod max_substring {
+    use super::*;
+
+    #[test]
+    fn test_empty_string() {
+        assert_eq!(max_substring(""), (0, 0, 0));
+    }
+
+    #[test]
+    fn test_single_character_string() {
+        assert_eq!(max_substring("a"), (0, 0, 1));
+    }
+
+    #[test]
+    fn test_all_same_characters() {
+        assert_eq!(max_substring("aaaaa"), (0, 0, 1));
+    }
+
+    #[test]
+    fn test_no_repeating_characters() {
+        assert_eq!(max_substring("abcde"), (0, 4, 5));
+    }
+
+    #[test]
+    fn test_repeating_characters() {
+        assert_eq!(max_substring("abcabcbb"), (0, 2, 3));
+    }
+
+    #[test]
+    fn test_mixed_characters() {
+        assert_eq!(max_substring("pwwkew"), (2, 4, 3));
+    }
+
+    #[test]
+    fn test_with_numbers() {
+        assert_eq!(max_substring("123456789012345678901234567890"), (0, 9, 10));
+    }
+
+    #[test]
+    fn test_with_special_characters() {
+        assert_eq!(max_substring("!@#$%^&*(*)_+"), (0, 8, 9));
+    }
+
+    #[test]
+    fn test_long_string_with_repeating_characters() {
+        assert_eq!(max_substring("dvdf"), (1, 3, 3));
+    }
+
+    #[test]
+    fn test_string_with_repeating_characters_at_end() {
+        assert_eq!(max_substring("abcdefgg"), (0, 6, 7));
+    }
+
+    #[test]
+    fn test_string_with_repeating_characters_at_start() {
+        assert_eq!(max_substring("bbbbb"), (0, 0, 1));
+    }
+}
diff --git a/src/string/mod.rs b/src/string/mod.rs
new file mode 100644
index 0000000..545560b
--- /dev/null
+++ b/src/string/mod.rs
@@ -0,0 +1,2 @@
+pub mod max_substring;
+pub use max_substring::*;