Update random-pick-with-weight.cpp

kamyu104 · web-flow · commit 29a1d204621a · 2018-07-29T02:33:26.000+08:00
diff --git a/C++/random-pick-with-weight.cpp b/C++/random-pick-with-weight.cpp
@@ -1,4 +1,5 @@
-// Time:  O(logn)
+// Time:  ctor: O(n)
+//        pickIndex: O(logn)
 // Space: O(n)
 
 class Solution {
