Adding latest stats

src/stats.rs

@@ -1,16 +1,16 @@
-use std::convert::TryFrom;
 use ::std::collections::HashMap;
-
+use std::convert::TryFrom;
 
 #[derive(Debug)]
-pub struct NewStatsCalculator<'a> {
-    data: &'a mut Vec<i32>,
+pub struct NewStatsCalculator {
+    data: Vec<i32>,
     length: u32,
     total: i32,
 }
 
-impl<'a> NewStatsCalculator<'a> {
-    pub fn from_vec(initial_data: &'a mut Vec<i32>) -> Self {
+impl NewStatsCalculator {
+    pub fn from_vec(initial_data: &[i32]) -> Self {
+        let initial_data = initial_data.to_vec();
         let mut instance = NewStatsCalculator {
             data: initial_data,
             length: 0,
@@ -65,14 +65,26 @@ impl<'a> NewStatsCalculator<'a> {
         }
     }
 
-    // pub fn get_mode(&self) -> HashMap<&mut i32, i32> {
-    //     let mut mode = HashMap::new();
-    //     for ref i in self.data {
-    //         let count = mode.entry(i).or_insert(0);
-    //         *count += 1;
-    //     }
-    //     mode
-    // }
+    pub fn get_mode(&self) -> Option<(i32, i32)> {
+        let mut mode: HashMap<i32, i32> = HashMap::new();
+        for i in &self.data {
+            let count = mode.entry(*i).or_insert(0);
+            *count += 1;
+        }
+        let mut mode_value: Option<(i32, i32)> = mode
+            .iter()
+            .max_by(|a, b| a.1.cmp(b.1))
+            .map(|(k, v)| (*k, *v));
+
+        if let Some((_, v)) = mode_value {
+            if v == 1 {
+                mode_value = None
+            }
+        }
+
+        // println!("{:?}", mode_value);
+        mode_value
+    }
 }
 
 #[cfg(test)]
@@ -81,38 +93,52 @@ mod test {
 
     #[test]
     fn test_get_length() {
-        let mut data = vec![1, 2, 3, 4, 5, 6];
-        let mut test = NewStatsCalculator::from_vec(&mut data);
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let mut test = NewStatsCalculator::from_vec(&data);
         test.get_length();
         assert_eq!(test.length, 6);
     }
 
     #[test]
     fn test_get_total() {
-        let mut data = vec![1, 2, 3, 4, 5, 6];
-        let mut test = NewStatsCalculator::from_vec(&mut data);
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let mut test = NewStatsCalculator::from_vec(&data);
         test.get_length();
         assert_eq!(test.total, 21);
     }
 
     #[test]
     fn test_get_mean() {
-        let mut data = vec![1, 2, 3, 4, 5, 6];
-        let test = NewStatsCalculator::from_vec(&mut data);
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let test = NewStatsCalculator::from_vec(&data);
         assert_eq!(test.get_mean(), 3.5);
     }
 
     #[test]
     fn test_get_median_even() {
-        let mut data = vec![1, 2, 3, 4, 5, 6];
-        let mut test = NewStatsCalculator::from_vec(&mut data);
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let mut test = NewStatsCalculator::from_vec(&data);
         assert_eq!(test.get_median(), 3.5);
     }
 
     #[test]
     fn test_get_median_odd() {
-        let mut data = vec![1, 2, 3, 4, 5, 6, 7];
-        let mut test = NewStatsCalculator::from_vec(&mut data);
+        let data = vec![1, 2, 3, 4, 5, 6, 7];
+        let mut test = NewStatsCalculator::from_vec(&data);
         assert_eq!(test.get_median(), 4.0);
     }
+
+    #[test]
+    fn test_get_mode_with_mode() {
+        let data = vec![1, 2, 3, 4, 5, 6, 6];
+        let test = NewStatsCalculator::from_vec(&data);
+        assert_eq!(test.get_mode(), Some((6, 2)))
+    }
+
+    #[test]
+    fn test_get_mode_without_mode() {
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let test = NewStatsCalculator::from_vec(&data);
+        assert_eq!(test.get_mode(), None)
+    }
 }