Update check-if-array-pairs-are-divisible-by-k.cpp

Author: kamyu104

C++/check-if-array-pairs-are-divisible-by-k.cpp

@@ -11,10 +11,15 @@ class Solution {
         for (const auto& i : arr) {
             ++count[(i % k + k) % k];
         }
-        for (int i = 0; i < k; ++i) {
-            if ((!i && count[i] % 2) ||
-                (i && count[i] != count[k - i])) {
-                    return false;
+        if (count.count(0) && count[0] % 2) {
+            return false;
+        }
+        for (int i = 1; i < k; ++i) {
+            if (!count.count(i)) {
+                continue;
+            }
+            if (!(count.count(k - i) && count[i] == count[k - i])) {
+                return false;
             }
         }
         return true;