Create divide-players-into-teams-of-equal-skill.cpp

Author: kamyu104

C++/divide-players-into-teams-of-equal-skill.cpp

@@ -0,0 +1,22 @@
+// Time:  O(n)
+// Space: O(n)
+
+// freq table
+class Solution {
+public:
+    long long dividePlayers(vector<int>& skill) {
+        const int64_t target = accumulate(cbegin(skill), cend(skill), 0ll) / (size(skill) / 2);
+        unordered_map<int, int> cnt;
+        for (const auto& s : skill) {
+            ++cnt[s];
+        }
+        int64_t result = 0;
+        for (const auto& [k, v] : cnt) {
+            if (!cnt.count(target - k) || cnt[target - k] != cnt[k]) {
+                return -1;
+            }
+            result += k * (target - k) * v;
+        }
+        return result / 2;
+    }
+};