Check for the presence of all values in MultiIndex.isin (#13879)

Fixes: #13861 

This PR fixes an issue in `MulitIndex.isin` where, previously we calculated partial matches. With this PR we will only return `True` for complete matches.

Authors:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

Approvers:
  - Bradley Dice (https://github.com/bdice)

URL: #13879

python/cudf/cudf/core/multiindex.py

@@ -730,18 +730,12 @@ def isin(self, values, level=None):
                 values_idx = cudf.MultiIndex.from_tuples(
                     values, names=self.names
                 )
-
-            res = []
-            for name in self.names:
-                level_idx = self.get_level_values(name)
-                value_idx = values_idx.get_level_values(name)
-
-                existence = level_idx.isin(value_idx)
-                res.append(existence)
-
-            result = res[0]
-            for i in res[1:]:
-                result = result & i
+            self_df = self.to_frame(index=False).reset_index()
+            values_df = values_idx.to_frame(index=False)
+            idx = self_df.merge(values_df)._data["index"]
+            res = cudf.core.column.full(size=len(self), fill_value=False)
+            res[idx] = True
+            result = res.values
         else:
             level_series = self.get_level_values(level)
             result = level_series.isin(values)

python/cudf/cudf/tests/test_index.py

@@ -2235,11 +2235,15 @@ def test_isin_index(data, values):
             [[1, 2, 3, 10, 100], ["red", "blue", "green", "pink", "white"]],
             names=("number", "color"),
         ),
+        pd.MultiIndex.from_product(
+            [[0, 1], ["red", "blue", "green"]], names=("number", "color")
+        ),
     ],
 )
 @pytest.mark.parametrize(
     "values,level,err",
     [
+        ([(1, "red"), (2, "blue"), (0, "green")], None, None),
         (["red", "orange", "yellow"], "color", None),
         (["red", "white", "yellow"], "color", None),
         ([0, 1, 2, 10, 11, 15], "number", None),