Create mice-and-cheese.cpp

Author: kamyu104

C++/mice-and-cheese.cpp

@@ -0,0 +1,15 @@
+// Time:  O(n)
+// Space: O(1)
+
+// greedy, quick select
+class Solution {
+public:
+    int miceAndCheese(vector<int>& reward1, vector<int>& reward2, int k) {
+        for (int i = 0; i < size(reward1); ++i) {
+            reward1[i] -= reward2[i];
+        }
+        nth_element(begin(reward1), begin(reward1) + (k - 1), end(reward1), greater<int>());
+        return accumulate(cbegin(reward1), cbegin(reward1) + k,
+                          accumulate(cbegin(reward2), cend(reward2), 0));
+    }
+};