test: add sliding window maximum spec

Author: bujosa

src/hard/sliding_window_maximum.rs

@@ -0,0 +1,21 @@
+#![allow(dead_code)]
+pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_max_sliding_window() {
+        assert_eq!(
+            max_sliding_window(vec![1, 3, -1, -3, 5, 3, 6, 7], 3),
+            vec![3, 3, 5, 5, 6, 7]
+        );
+
+        assert_eq!(max_sliding_window(vec![1], 1), vec![1]);
+
+        assert_eq!(max_sliding_window(vec![1, -1], 1), vec![1, -1]);
+
+        assert_eq!(max_sliding_window(vec![9, 11], 2), vec![11]);
+    }
+}