some tests passed in clock

rust/clock/src/lib.rs

@@ -0,0 +1,61 @@
+#[derive(Debug)]
+pub struct Clock {
+    pub hours: i32,
+    pub minutes: i32,
+}
+
+impl Clock {
+    pub fn new(hours: i32, minutes: i32) -> Self {
+        Clock { hours, minutes }
+    }
+
+    /*
+    40 => 0 (0*60 + 40 - 60*0)
+    60 => 1 (1*60 + 60 - 60*1)
+    90 => 1 (1*60 + 90 - 60*1)
+    150 => 150/60 = 2, (2*60 + 150 - 60*2)
+
+    23 => 23 (23 - 24 * 0)
+    26 => 2 (hours - 24 * hours_diff)
+    49 => 1 (hours - 24 * hours_diff)
+    */
+
+    pub fn add_minutes(&self, minutes: i32) -> Self {
+        let hours_diff: i32 = (minutes as i32) / 60_i32;
+        let hours = self.hours + hours_diff;
+        let minutes = hours_diff*60 + minutes - 60*hours_diff;
+        let hours_diff = hours / 24_i32;
+        let hours = hours - 24 * hours_diff;
+        Clock { hours, minutes }
+    }
+    pub fn to_string(&self) -> String {
+        let hours = match self.hours.cmp(&10) {
+            std::cmp::Ordering::Less => format!("0{}",self.hours),
+            std::cmp::Ordering::Equal => format!("{}", self.hours),
+            std::cmp::Ordering::Greater => format!("{}", self.hours),
+        };
+        let minutes = match self.minutes.cmp(&10) {
+            std::cmp::Ordering::Less => format!("0{}",self.minutes),
+            std::cmp::Ordering::Equal => format!("{}", self.minutes),
+            std::cmp::Ordering::Greater => format!("{}", self.minutes),
+        };
+        format!("{}:{}", hours, minutes)
+    }
+
+}
+
+impl PartialEq for Clock {
+    fn eq(&self, other: &Self) -> bool {
+        match self.hours.cmp(&other.hours) {
+            std::cmp::Ordering::Less => false,
+            std::cmp::Ordering::Equal => {
+                match self.minutes.cmp(&other.minutes) {
+                    std::cmp::Ordering::Less => false,
+                    std::cmp::Ordering::Equal => true,
+                    std::cmp::Ordering::Greater => false,
+                }
+            },
+            std::cmp::Ordering::Greater => false,
+        }
+    }
+}