Update find-array-given-subset-sums.cpp

Author: kamyu104

C++/find-array-given-subset-sums.cpp

@@ -16,7 +16,7 @@
 //      => [-d]+[(-x1), ..., (-xi)]+[x(i+1), ..., x(n-1)] is also a solution
 //
 // [conclusion]
-// - if new_sums with +d/-d both contain zero, we can choose either one
+// - if new_sums with +d/-d (including d = 0) both contain zero, we can choose either one
 // - if only one of new_sums with +d/-d contains zero, we can only choose the one with zero since subset_sums must contain zero
 
 // optimized from solution4 (not using unordered_map), runtime: 188 ms