Merge pull request #225 from ben1009/551

feat: 551

src/problem/mod.rs

@@ -46,6 +46,7 @@ pub mod p0496_next_greater_element_i;
 pub mod p0503_next_greater_element_ii;
 pub mod p0521_longest_uncommon_subsequence;
 pub mod p0543_diameter_of_binary_tree;
+pub mod p0551_student_attendance_record_i;
 pub mod p0560_subarray_sum_equals_k;
 pub mod p0581_shortest_unsorted_continuous_subarray;
 pub mod p0617_merge_two_binary_trees;

src/problem/p0551_student_attendance_record_i.rs

@@ -0,0 +1,72 @@
+// You are given a string s representing an attendance record for a student where each character
+// signifies whether the student was absent, late, or present on that day. The record only contains
+// the following three characters:
+
+// 'A': Absent.
+// 'L': Late.
+// 'P': Present.
+// The student is eligible for an attendance award if they meet both of the following criteria:
+
+// The student was absent ('A') for strictly fewer than 2 days total.
+// The student was never late ('L') for 3 or more consecutive days.
+// Return true if the student is eligible for an attendance award, or false otherwise.
+
+// Example 1:
+
+// Input: s = "PPALLP"
+// Output: true
+// Explanation: The student has fewer than 2 absences and was never late 3 or more consecutive days.
+// Example 2:
+
+// Input: s = "PPALLL"
+// Output: false
+// Explanation: The student was late 3 consecutive days in the last 3 days, so is not eligible for
+// the award.
+
+// Constraints:
+
+// 1 <= s.length <= 1000
+// s[i] is either 'A', 'L', or 'P'.
+
+// https://leetcode.com/problems/student-attendance-record-i/
+
+pub struct Solution {}
+
+impl Solution {
+    pub fn check_record(s: String) -> bool {
+        if s.len() < 2 {
+            return true;
+        }
+
+        let mut a = 0;
+        let mut l = 0;
+        let s = s.as_bytes();
+        for i in 0..s.len() {
+            if s[i] == b'L' {
+                if i == 0 || s[i - 1] != b'L' {
+                    l = 1;
+                } else {
+                    l += 1;
+                    if l == 3 {
+                        return false;
+                    }
+                }
+            } else if s[i] == b'A' {
+                a += 1;
+            }
+        }
+
+        a < 2
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_0551() {
+        assert!(Solution::check_record("PPALLP".to_string()));
+        assert!(!Solution::check_record("PPALLL".to_string()));
+    }
+}