mer

Author: grifill

examples/arrays-sort/src/main.rs

@@ -68,3 +68,45 @@ fn binary_search_first(arr: &[i32], target: i32) -> Option<usize> {
     }
     result
 }
+
+fn merge_sort(arr: &mut [i32]) {
+    if arr.len() <= 1 {
+        return;
+    }
+
+    let mid = arr.len() / 2;
+    let mut left = arr[..mid].to_vec();
+    let mut right = arr[mid..].to_vec();
+
+    merge_sort(&mut left);
+    merge_sort(&mut right);
+
+    merge(arr, &left, &right);
+}
+
+fn merge(arr: &mut [i32], left: &[i32], right: &[i32]) {
+    let (mut i, mut j, mut k) = (0, 0, 0);
+
+    while i < left.len() && j < right.len() {
+        if left[i] <= right[j] {
+            arr[k] = left[i];
+            i += 1;
+        } else {
+            arr[k] = right[j];
+            j += 1;
+        }
+        k += 1;
+    }
+
+    while i < left.len() {
+        arr[k] = left[i];
+        i += 1;
+        k += 1;
+    }
+
+    while j < right.len() {
+        arr[k] = right[j];
+        j += 1;
+        k += 1;
+    }
+}