20240818 Finished

TEST

@@ -0,0 +1,24 @@
+ 1. Move the cursor to this line.
+
+ 2. Press [v](v) and move the cursor to the fifth item below. Notice that the
+    text is highlighted.
+
+ 3. Press the `:`{normal} character. At the bottom of the screen
+
+        `:'<,'>`{vim}
+
+    will appear.
+
+ 4. Type
+
+        `w TEST`{vim}
+
+    where TEST is a filename that does not exist yet. Verify that you see
+
+        `:'<,'>w TEST`{vim}
+
+    before you press `<Enter>`{normal}.
+
+ 5. Neovim will write the selected lines to the file TEST. Use `:!ls`{vim} to see it.
+    Do not remove it yet! We will use it in the next lesson.
+

src/problem/mod.rs

@@ -208,3 +208,4 @@ mod p188_best_time_to_buy_and_sell_stock_iv;
 mod p221_maximal_square;
 mod p3117_minimum_sum_of_values_by_dividing_array;
 mod p3137_minimum_number_of_operations_to_make_word_k_periodic;
+mod p551_student_attendance_record_i;

src/problem/p551_student_attendance_record_i.rs

@@ -0,0 +1,49 @@
+/**
+ * [551] Student Attendance Record I
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn check_record(s: String) -> bool {
+        let s: Vec<char> = s.chars().collect();
+        let mut late_count = 0;
+        let mut absent_count = 0;
+        
+        for c in s {
+            match c {
+                'A' => {
+                    absent_count += 1;
+                    late_count = 0;
+                    
+                    if absent_count >= 2 {
+                        return false;
+                    }
+                },
+                'L' => {
+                    late_count += 1;
+                    
+                    if late_count >= 3 {
+                        return false;
+                    }
+                },
+                _ => {
+                    late_count = 0;
+                }
+            }
+        }
+        
+        true
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_551() {}
+}