Add problem 0657: Robot Return to Origin

src/lib.rs

@@ -386,6 +386,7 @@ pub mod problem_0648_replace_words;
 pub mod problem_0650_2_keys_keyboard;
 pub mod problem_0653_two_sum_iv_input_is_a_bst;
 pub mod problem_0654_maximum_binary_tree;
+pub mod problem_0657_robot_return_to_origin;
 pub mod problem_0665_non_decreasing_array;
 pub mod problem_0670_maximum_swap;
 pub mod problem_0673_number_of_longest_increasing_subsequence;

src/problem_0657_robot_return_to_origin/iterative.rs

@@ -0,0 +1,31 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn judge_circle(moves: String) -> bool {
+        let mut pos = (0, 0);
+        for ch in moves.chars() {
+            match ch {
+                'R' => pos.0 += 1,
+                'L' => pos.0 -= 1,
+                'U' => pos.1 += 1,
+                'D' => pos.1 -= 1,
+                _ => unreachable!(),
+            }
+        }
+        pos == (0, 0)
+    }
+}
+
+impl super::Solution for Solution {
+    fn judge_circle(moves: String) -> bool {
+        Self::judge_circle(moves)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_0657_robot_return_to_origin/mod.rs

@@ -0,0 +1,23 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn judge_circle(moves: String) -> bool;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            ("UD", true),
+            ("LL", false),
+            ("RRDD", false),
+            ("LDRRLRUULR", false),
+        ];
+
+        for (moves, expected) in test_cases {
+            assert_eq!(S::judge_circle(moves.to_string()), expected);
+        }
+    }
+}