fixed find maxima function first 3

hands_on/local_maxima_part2/local_maxima.py

@@ -7,4 +7,22 @@ def find_maxima(x):
     Output:
     idx -- list of indices of the local maxima in x
     """
-    return []
+    localmax = []
+
+    for i, num in enumerate(x):
+        if i == 0:
+            if x[i+1] < x[i]:
+                localmax.append(i)
+        elif i == len(x)-1:
+            if x[i-1] < x[i]:
+                localmax.append(i)
+        else:
+            if x[i+1] < x[i] and x[i-1] < x[i]:
+                localmax.append(i)
+
+    return localmax
+
+
+if __name__ == "__main__":
+    x = [1, 2, 3]
+    print(find_maxima(x))