From df1fa87bb3babf74b4a319287d550b620c63ca3d Mon Sep 17 00:00:00 2001
From: Bauke <me@bauke.xyz>
Date: Wed, 6 Apr 2022 14:31:17 +0200
Subject: [PATCH] Solve reverse-integer.

---
 source/lib.rs                 |  1 +
 source/reverse_integer/mod.rs | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 source/reverse_integer/mod.rs

diff --git a/source/lib.rs b/source/lib.rs
index 40aceb0..9823fe9 100644
--- a/source/lib.rs
+++ b/source/lib.rs
@@ -1 +1,2 @@
+pub mod reverse_integer;
 pub mod two_sum;
diff --git a/source/reverse_integer/mod.rs b/source/reverse_integer/mod.rs
new file mode 100644
index 0000000..72aaf47
--- /dev/null
+++ b/source/reverse_integer/mod.rs
@@ -0,0 +1,26 @@
+pub fn reverse(number: i32) -> i32 {
+  number
+    // Convert to an absolute number without wrapping or panicking.
+    .unsigned_abs()
+    // Convert the number to string, then reverse all its characters.
+    .to_string()
+    .chars()
+    .rev()
+    // Collect the reversed characters back into a string.
+    .collect::<String>()
+    // Parse the string into an i32.
+    .parse()
+    // If it returns an Err then use 0 instead.
+    .unwrap_or(0)
+    // Then multiply by 0, 1 or -1 depending on the sign of the original number.
+    * number.signum()
+}
+
+#[test]
+fn test_reverse_integer() {
+  assert_eq!(reverse(123), 321);
+  assert_eq!(reverse(-123), -321);
+  assert_eq!(reverse(120), 21);
+  assert_eq!(reverse(i32::MAX), 0);
+  assert_eq!(reverse(i32::MIN), 0);
+}