Create partition-labels.cpp

C++/partition-labels.cpp

@@ -0,0 +1,22 @@
+// Time:  O(n)
+// Space: O(n)
+
+class Solution {
+public:
+    vector<int> partitionLabels(string S) {
+        unordered_map<int, int> lookup;
+        for (int i = 0; i < S.length(); ++i) {
+            lookup[S[i]] = i;
+        }
+        int first = 0, last = 0;
+        vector<int> result;
+        for (int i = 0; i < S.length(); ++i) {
+            last = max(last, lookup[S[i]]);
+            if (i == last) {
+                result.emplace_back(i - first + 1);
+                first = i + 1;
+            }
+        }
+        return result;
+    }
+};