general: ex2: add solution

general/ex2.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+
+def skip_first(arr: list[int]) -> list[int]:
+    if len(arr) <= 1:
+        return []
+
+    first = arr[0]
+    for i in range(1, len(arr)):
+        if first != arr[i]:
+            break
+    # The loop must have iterated at least once, i is bound
+    return arr[i:]  # type: ignore
+
+
+def solution(arr: list[int], other: list[int]) -> list[int]:
+    res = []
+    while True:
+        if not arr or not other:
+            break
+        a = arr[0]
+        b = other[0]
+        if a == b:
+            res.append(a)
+        if a <= b:
+            arr = skip_first(arr)
+        if b <= a:
+            other = skip_first(other)
+    return res
+
+
+def pythonic_solution(arr: list[int], other: list[int]) -> list[int]:
+    return list(set(arr) & set(other))
+
+
+if __name__ == "__main__":
+    arr1 = [0, 1, 2, 3, 4, 5, 5, 5, 6, 7]
+    arr2 = [0, 0, 3, 3, 3, 5, 6, 6, 7, 8]
+    print(solution(arr1, arr2))
+    print(pythonic_solution(arr1, arr2))