2350

Author: mkmark

leetcode/2350/0.in

@@ -0,0 +1,2 @@
+[4,2,1,2,3,3,2,4,1]
+4

leetcode/2350/main.cpp

@@ -0,0 +1,39 @@
+/*
+author: [email protected]
+*/
+
+#include <bits/stdc++.h>
+#include "../../lib/LeetCodeInput.hpp"
+#include "solution-2.cpp"
+using namespace std;
+
+int main()
+{
+    LeetCodeInput li("0.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.shortestSequence(arr_1, num_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/2350/solution-2.cpp

@@ -0,0 +1,46 @@
+/*
+author: [email protected]
+time: O(n)
+space: O(k)
+
+Runtime: 83 ms, faster than 100.00% of C++ online submissions for Shortest Impossible Sequence of Rolls.
+Memory Usage: 86.9 MB, less than 95.12% of C++ online submissions for Shortest Impossible Sequence of Rolls.
+*/
+
+#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 shortestSequence(vector<int>& rolls, int k) {
+        int seen[k+1];
+        int memset_bytes = 4*k+4;
+        memset(seen, 0, memset_bytes);
+        int cnt = 0;
+        int res = 1;
+        for (auto & roll : rolls){
+            if (!seen[roll]){
+                seen[roll] = 1;
+                ++cnt;
+                if (cnt == k){
+                    memset(seen, 0, memset_bytes);
+                    ++res;
+                    cnt = 0;
+                }
+            }
+        }
+        return res;
+    }
+};
+
+const static auto initialize = [] {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::cout.tie(nullptr);
+    return nullptr;
+}();

leetcode/2350/solution.cpp

@@ -0,0 +1,62 @@
+/*
+author: [email protected]
+time: O()
+space: O()
+
+Runtime: 218 ms, faster than 93.81% of C++ online submissions for Shortest Impossible Sequence of Rolls.
+Memory Usage: 113.7 MB, less than 54.58% of C++ online submissions for Shortest Impossible Sequence of Rolls.
+*/
+
+#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 shortestSequence(vector<int>& rolls, int k) {
+        /// position sequence of any given number
+        vector<vi> pos_seqs(k+1);
+        int pos = 0;
+        for (auto & roll : rolls){
+            pos_seqs[roll].push_back(pos++);
+        }
+
+        /// position of any given number now
+        vector<vi::iterator> pos_now_its(k+1);
+        int res = 1;
+        int pos_next_min = 0;
+        for (int i=1; i<=k; ++i){
+            if (pos_seqs[i].size() == 0){
+                return res;
+            }
+            pos_now_its[i] = pos_seqs[i].begin();
+            pos_next_min = max(pos_next_min, pos_seqs[i][0]+1);
+        }
+
+        int pos_now_min;
+        vi::iterator it;
+        for (res = 2;; ++res){
+            pos_now_min = pos_next_min;
+            for (int i=1; i<=k; ++i){
+                it = lower_bound(pos_now_its[i], pos_seqs[i].end(), pos_now_min);
+                if (it == pos_seqs[i].end()){
+                    return res;
+                } else {
+                    pos_now_its[i] = it;
+                    pos_next_min = max(pos_next_min, *it+1);
+                }
+            }
+        }
+    }
+};
+
+const static auto initialize = [] {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::cout.tie(nullptr);
+    return nullptr;
+}();