hands_on/local_maxima_part2/local_maxima.py

@@ -7,4 +7,27 @@ def find_maxima(x):
     Output:
     idx -- list of indices of the local maxima in x
     """
-    return []
+    maxima = []
+    for idx in range(len(x)):
+        if idx == 0:
+            if x[idx] >= x[idx+1]:
+                maxima.append(idx)
+        elif idx == len(x)-1:
+            if x[idx] >= x[idx-1]:
+                maxima.append(idx)
+        else:
+            if x[idx] >= x[idx+1] and x[idx] >= x[idx-1]:
+                maxima.append(idx)
+    return maxima
+
+
+if __name__ == "__main__":
+    values = [
+    [1, 3, -2, 0, 2, 1],
+    [4,2,1,3,1,5],
+    [],
+    [1,2,2,1],
+    [1,2,2,3,1],
+    ]
+    for value in values:
+        print(find_maxima(value))

hands_on/local_maxima_part2/test_local_maxima.py

@@ -23,8 +23,14 @@ def test_find_maxima_empty():
 
 
 def test_find_maxima_plateau():
-    raise Exception('not yet implemented')
+    values = [1,2,2,1]
+    expected = [1,2]
+    maxima = find_maxima(values)
+    assert maxima == expected
     
 
 def test_find_maxima_not_a_plateau():
-    raise Exception('not yet implemented')
+    values = [1,2,2,3,1]
+    expected = [3]
+    maxima = find_maxima(values)
+    assert maxima == expected