Create describe-the-painting.cpp

Author: kamyu104

C++/describe-the-painting.cpp

@@ -0,0 +1,26 @@
+// Time:  O(nlogn)
+// Space: O(n)
+
+class Solution {
+public:
+    vector<vector<long long>> splitPainting(vector<vector<int>>& segments) {
+        unordered_map<int, int64_t> events;
+        for (const auto& s : segments) {
+            events[s[0]] += s[2];
+            events[s[1]] -= s[2];
+        }
+        vector<pair<int, int64_t>> points(cbegin(events), cend(events));
+        sort(begin(points), end(points));
+
+        vector<vector<long long>> result;
+        int64_t overlap = 0, prev = 0;
+        for (const auto& [curr, cnt] : points) {
+            if (overlap) {
+                result.push_back({prev, curr, overlap});
+            }
+            overlap += cnt;
+            prev = curr;
+        }
+        return result;
+    }
+};