solve 32

Author: Zhang Xiaodong

src/solution/mod.rs

@@ -27,3 +27,4 @@ mod s0028_find_the_index_of_the_first_occurrence_in_a_string;
 mod s0029_divide_two_integers;
 mod s0030_substring_with_concatenation_of_all_words;
 mod s0031_next_permutation;
+mod s0032_longest_valid_parentheses;

src/solution/s0032_longest_valid_parentheses.rs

@@ -0,0 +1,83 @@
+use std::thread::current;
+
+/**
+ * [32] 最长有效括号
+ *
+ * 给你一个只包含 '(' 和 ')' 的字符串，找出最长有效（格式正确且连续）括号子串的长度。
+ *  
+ * <div class="original__bRMd">
+ * <div>
+ * 示例 1：
+ * 
+ * 输入：s = "(()"
+ * 输出：2
+ * 解释：最长有效括号子串是 "()"
+ * 
+ * 示例 2：
+ * 
+ * 输入：s = ")()())"
+ * 输出：4
+ * 解释：最长有效括号子串是 "()()"
+ * 
+ * 示例 3：
+ * 
+ * 输入：s = ""
+ * 输出：0
+ * 
+ *  
+ * 提示：
+ * 
+ * 	0 <= s.length <= 3 * 10^4
+ * 	s[i] 为 '(' 或 ')'
+ * </div>
+ * </div>
+ * 
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.cn/problems/longest-valid-parentheses/
+// discuss: https://leetcode.cn/problems/longest-valid-parentheses/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn longest_valid_parentheses(s: String) -> i32 {
+        let mut parenthesses = vec![];
+        let mut max_num = 0;
+        let mut cur_num = 0;
+        for b in s.as_bytes() {
+            if *b == b'(' {
+                parenthesses.push(b);
+                continue;
+            }
+            if parenthesses.len() == 0 {
+                if cur_num > max_num {
+                    max_num = cur_num;
+                }
+                cur_num = 0;
+                parenthesses.clear();
+                continue;
+            }
+            parenthesses.pop();
+            cur_num += 1;
+        }
+        if cur_num > max_num {
+            max_num = cur_num;
+        }
+        max_num << 1
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_32() {
+        assert_eq!(Solution::longest_valid_parentheses("(()".to_string()), 2);
+        assert_eq!(Solution::longest_valid_parentheses(")()())".to_string()), 4);
+        assert_eq!(Solution::longest_valid_parentheses("".to_string()), 0);
+    }
+}