84

Author: mkmark

leetcode/84/0.in

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+[2,1,5,6,2,3]

leetcode/84/2.in

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+[2,4]

leetcode/84/24.in

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+[1,1]

leetcode/84/49.in

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+[2,1,2]

leetcode/84/63.in

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+[4,2,0,3,2,5]

leetcode/84/main.cpp

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+/*
+author: [email protected]
+*/
+
+#include <bits/stdc++.h>
+#include "../../lib/LeetCodeInputTemplate.hpp"
+#include "solution-2.cpp"
+using namespace std;
+
+typedef vector<int> vi;
+typedef vector<vector<int>> vvi;
+
+int main()
+{
+    LeetCodeInput li("0.in");
+
+    auto l0 = li.get<vi>(0);
+
+    chrono::steady_clock::time_point begin = chrono::steady_clock::now();
+    Solution solution;
+    auto output = solution.largestRectangleArea(l0);
+    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/84/solution-2.cpp

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+/*
+author: [email protected]
+time: O(n)
+space: O(n)
+
+Runtime: 153 ms, faster than 99.36% of C++ online submissions for Largest Rectangle in Histogram.
+Memory Usage: 76.5 MB, less than 77.82% of C++ online submissions for Largest Rectangle in Histogram.
+*/
+
+#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:
+    int largestRectangleArea(vector<int>& heights) {
+        int ans = 0;
+        stack<pair<int,int>> ms;
+        int n = size(heights);
+        // int ls[n];
+        int rs[n];
+
+        for (int i=n-1; i>=0; --i){
+            int height = heights[i];
+            while (!ms.empty() && ms.top().first>=height){
+                ms.pop();
+            }
+            rs[i] = ms.empty() ? n : ms.top().second;
+            ms.emplace(height,i);
+        }
+
+        ms = {};
+
+        for (int i=0; i<n; ++i){
+            int height = heights[i];
+            while (!ms.empty() && ms.top().first>=height){
+                ms.pop();
+            }
+            // ls[i] = ms.empty() ? -1 : ms.top().second;
+            int l = ms.empty() ? -1 : ms.top().second;
+            ans = max(ans, height*(rs[i]-l-1));
+            ms.emplace(height,i);
+        }
+
+        return ans;
+    }
+};
+
+const static auto initialize = [] {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::cout.tie(nullptr);
+    return nullptr;
+}();

leetcode/84/solution.cpp

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+/*
+author: [email protected]
+time: O(n)
+space: O(n)
+
+Runtime: 157 ms, faster than 99.08% of C++ online submissions for Largest Rectangle in Histogram.
+Memory Usage: 76.9 MB, less than 77.52% of C++ online submissions for Largest Rectangle in Histogram.
+*/
+
+#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:
+    int largestRectangleArea(vector<int>& heights) {
+        int ans = 0;
+        stack<pair<int,int>> ms;
+        int n = size(heights);
+        int ls[n];
+        int rs[n];
+
+        for (int i=n-1; i>=0; --i){
+            int height = heights[i];
+            while (!ms.empty() && ms.top().first>=height){
+                ms.pop();
+            }
+            rs[i] = ms.empty() ? n : ms.top().second;
+            ms.emplace(height,i);
+        }
+
+        ms = {};
+
+        for (int i=0; i<n; ++i){
+            int height = heights[i];
+            while (!ms.empty() && ms.top().first>=height){
+                ms.pop();
+            }
+            ls[i] = ms.empty() ? -1 : ms.top().second;
+            int l = ms.empty() ? -1 : ms.top().second;
+            ans = max(ans, height*(rs[i]-l-1));
+            ms.emplace(height,i);
+        }
+
+        return ans;
+    }
+};
+
+const static auto initialize = [] {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::cout.tie(nullptr);
+    return nullptr;
+}();