391

Author: mkmark

leetcode/391/a.in

@@ -0,0 +1 @@
+[[0,0,3,3],[1,1,2,2]]

leetcode/391/main.cpp

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+/*
+author: [email protected]
+*/
+
+#include <bits/stdc++.h>
+#include "../../lib/LeetCodeInput.hpp"
+#include "solution.cpp"
+using namespace std;
+
+int main()
+{
+    LeetCodeInput li("a.in");
+
+    vector<vector<int>> mat_1 = li.get_vvi(0);
+    // vector<int> arr_1 = li.get_vi(0);
+    // int num_1 = li.get_i(0);
+    // string s_1 = li.get_s(0);
+
+    chrono::steady_clock::time_point begin = chrono::steady_clock::now();
+    Solution solution;
+    auto output = solution.isRectangleCover(mat_1);
+    chrono::steady_clock::time_point end = chrono::steady_clock::now();
+    cout << "Time difference = " << chrono::duration_cast<chrono::microseconds> (end - begin).count() << "µs" << endl;
+
+    cout << output << endl;
+
+    // for (int i: output){
+    //     cout << i << ' ';
+    // }
+
+    // for (auto i: output){
+    //     for (int j: i){
+    //         cout << j << ' ';
+    //     }
+    //     cout << '\n';
+    // }
+
+    return 0;
+}

leetcode/391/solution.cpp

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+/*
+author: [email protected]
+time: O(nlog(n))
+space: O(n)
+
+Runtime: 129 ms, faster than 94.04% of C++ online submissions for Perfect Rectangle.
+Memory Usage: 37.9 MB, less than 20.00% of C++ online submissions for Perfect Rectangle.
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define all(x) begin(x), end(x)
+typedef vector<int> vi;
+typedef vector<vector<int>> vvi;
+
+class Solution {
+public:
+    bool isRectangleCover(vector<vector<int>>& rectangles) {
+        /// stream[y] = { open_map, close_map }
+        /// x_map[x1] = x2
+        map<int, array<map<int, int>, 2>> stream;
+        for (auto & rect : rectangles){
+            if (stream[rect[1]][0].find(rect[0]) != stream[rect[1]][0].end() && stream[rect[1]][0][rect[0]] == rect[2]) return false;
+            stream[rect[1]][0].insert({rect[0], rect[2]});
+            stream[rect[3]][1].insert({rect[0], rect[2]});
+        }
+
+        /// merge bottom
+        if (!merge_ranges((*begin(stream)).second[0])) return false;
+        /// bottom check
+        if ((*stream.begin()).second[0].size() != 1) return false;
+        /// merge top
+        if (!merge_ranges((*rbegin(stream)).second[1])) return false;
+        /// top check
+        if ((*rbegin(stream)).second[1] != (*begin(stream)).second[0]) return false;
+        /// middle check
+        auto it_end = prev((stream.end()));
+        for (auto it = next(stream.begin()); it != it_end; ++it){
+            if (!merge_ranges((*it).second[0])) return false;
+            if (!merge_ranges((*it).second[1])) return false;
+            if ((*it).second[0] != (*it).second[1]) return false;
+        }
+
+        return true;
+    }
+
+    inline bool merge_ranges(std::map<int, int> & ranges){
+        /// empty range does not equal nonempty ones, but would cause infinite loop
+        if (ranges.empty()) return false;
+        auto former = begin(ranges);
+        auto cur = next(begin(ranges));
+        map<int, int>::iterator to_erase;
+        while (cur != end(ranges)){
+            if ((*cur).first == (*former).second){
+                (*former).second = (*cur).second;
+                to_erase = cur++;
+                ranges.erase(to_erase);
+            } else if ((*cur).first < (*former).second){
+                return false;
+            } else {
+                former = cur;
+                ++cur;
+            }
+        }
+        return true;
+    }
+};
+
+const static auto initialize = [] {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::cout.tie(nullptr);
+    return nullptr;
+}();