Create minimum-levels-to-gain-more-points.cpp

Author: kamyu104

C++/minimum-levels-to-gain-more-points.cpp

@@ -0,0 +1,19 @@
+// Time:  O(n)
+// Space: O(n)
+
+// prefix sum
+class Solution {
+public:
+    int minimumLevels(vector<int>& possible) {
+        vector<int> prefix(size(possible) + 1);
+        for (int i = 0; i < size(possible); ++i) {
+            prefix[i + 1] = prefix[i] + (possible[i] ? +1 : -1);
+        }
+        for (int i = 0; i + 1 < size(possible); ++i) {
+            if (prefix[i + 1] > prefix.back() - prefix[i + 1]) {
+                return i + 1;
+            }
+        }
+        return -1;
+    }
+};