Add wiggle_sort (TheAlgorithms#449)

domix80 · web-flow · commit 087c64534854 · 2023-02-07T08:51:39.000+02:00
diff --git a/src/sorting/wiggle_sort.rs b/src/sorting/wiggle_sort.rs
@@ -0,0 +1,54 @@
+//Wiggle Sort.
+//Given an unsorted array nums, reorder it such
+//that nums[0] < nums[1] > nums[2] < nums[3]....
+//For example:
+//if input numbers = [3, 5, 2, 1, 6, 4]
+//one possible Wiggle Sorted answer is [3, 5, 1, 6, 2, 4].
+
+pub fn wiggle_sort(nums: Vec<i32>) -> Vec<i32> {
+//Rust implementation of wiggle.
+//    Example:
+//    >>> wiggle_sort([0, 5, 3, 2, 2])
+//    [0, 5, 2, 3, 2]
+//    >>> wiggle_sort([])
+//    []
+//    >>> wiggle_sort([-2, -5, -45])
+//    [-45, -2, -5]
+
+    let len = nums.len();
+    let mut p = nums;
+    for i in 1..len {
+        let num_x = p[i - 1];
+        let num_y = p[i];
+        if (i % 2 == 1) == (num_x > num_y) {
+            p[i - 1] = num_y;
+            p[i] = num_x;
+        }
+    }
+    return p
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn wingle_elements() {
+        let arr = vec![3, 5, 2, 1, 6, 4];
+        let res = wiggle_sort(arr.clone());
+        assert_eq!(res, [3, 5, 1, 6, 2, 4]);
+    }
+    
+    #[test]
+    fn odd_number_of_elements() {
+        let arr = vec![4, 1, 3, 5, 2];
+        let res = wiggle_sort(arr.clone());
+        assert_eq!(res, [1, 4, 3, 5, 2]);
+    }
+
+    #[test]
+    fn repeated_elements() {
+        let arr = vec![5, 5, 5, 5];
+        let res = wiggle_sort(arr.clone());
+        assert_eq!(res, [5, 5, 5, 5]);
+    }
+}
