Create most-stones-removed-with-same-row-or-column.cpp

Author: kamyu104

C++/most-stones-removed-with-same-row-or-column.cpp

@@ -0,0 +1,43 @@
+// Time:  O(n)
+// Space: O(n)
+
+class Solution {
+public:
+    int removeStones(vector<vector<int>>& stones) {
+        static const int MAX_ROW = 10000;
+        UnionFind union_find(2 * MAX_ROW);
+        for (const auto& stone : stones) {
+            union_find.union_set(stone[0], stone[1] + MAX_ROW);
+        }
+        unordered_set<int> components;
+        for (const auto& stone : stones) {
+            components.emplace(union_find.find_set(stone[0]));
+        }
+        return stones.size() - components.size();
+    }
+
+private:
+    class UnionFind {
+    public:
+        UnionFind(const int n) : set_(n) {
+            iota(set_.begin(), set_.end(), 0);
+        }
+        
+        int find_set(const int x) {
+           if (set_[x] != x) {
+               set_[x] = find_set(set_[x]);  // Path compression.
+           }
+           return set_[x];
+        }
+
+        void union_set(const int x, const int y) {
+            int x_root = find_set(x), y_root = find_set(y);
+            if (x_root != y_root) {
+                set_[min(x_root, y_root)] = max(x_root, y_root);
+            }
+        }
+
+    private:
+        vector<int> set_;
+    };
+};