45-9kyo-hwang

9-kyo-hwang/Backtracking/6987 월드컵.cpp

@@ -0,0 +1,79 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+const vector<pair<int, int>> TeamMatches
+{
+    {0, 1}, {0, 2}, {0, 3}, {0, 4}, {0, 5}, 
+    {1, 2}, {1, 3}, {1, 4}, {1, 5},
+    {2, 3}, {2, 4}, {2, 5},
+    {3, 4}, {3, 5},
+    {4, 5},
+};
+
+const vector<pair<int, int>> MatchResultIndices
+{// 1 win,   tie,   2 win
+    {0, 2}, {1, 1}, {2, 0}
+};
+
+vector<vector<int>> MatchScore;
+
+bool Backtracking(int Match = 0)
+{
+    if(Match == TeamMatches.size())
+    {
+        for(const auto& Team : MatchScore)
+        {
+            if(count(Team.begin(), Team.end(), 0) != 3)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    const auto& [Team1, Team2] = TeamMatches[Match];
+    for(const auto& [i, j] : MatchResultIndices)
+    {
+        if(MatchScore[Team1][i] <= 0 || MatchScore[Team2][j] <= 0)
+        {
+            continue;
+        }
+
+        --MatchScore[Team1][i];
+        --MatchScore[Team2][j];
+
+        if(Backtracking(Match + 1))
+        {
+            return true;
+        }
+
+        ++MatchScore[Team1][i];
+        ++MatchScore[Team2][j];
+    }
+
+    return false;
+}
+
+int main()
+{
+    cin.tie(nullptr)->sync_with_stdio(false);
+
+    for(int T = 1; T <= 4; ++T)
+    {
+        MatchScore.assign(6, vector(3, 0));
+        for(auto& Team : MatchScore)
+        {
+            for(auto& Score : Team)
+            {
+                cin >> Score;
+            }
+        }
+        cout << Backtracking() << " ";
+    }
+
+    return 0;
+}

9-kyo-hwang/Data Structure/3015 오아시스 재결합.cpp

@@ -0,0 +1,39 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int main()
+{
+    cin.tie(nullptr)->sync_with_stdio(false);
+
+    int N; cin >> N;
+    vector<pair<int, int64_t>> Stack;
+
+    int64_t NumPair = 0;
+    while(N--)
+    {
+        int Height; cin >> Height;
+        int64_t NumSame = 1;
+
+        while(!Stack.empty() && Stack.back().first <= Height)
+        {
+            NumPair += Stack.back().second;
+            if(Stack.back().first == Height)
+            {
+                NumSame = Stack.back().second + 1;
+            }
+            Stack.pop_back();
+        }
+
+        if(!Stack.empty())
+        {
+            NumPair += 1;
+        }
+        Stack.emplace_back(Height, NumSame);
+    }
+
+    cout << NumPair;
+
+    return 0;
+}

9-kyo-hwang/Dynamic Programming/2240 자두나무.cpp

@@ -0,0 +1,55 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main()
+{
+    cin.tie(nullptr)->sync_with_stdio(false);
+
+    int T, W; cin >> T >> W;
+    vector<int> Poses(T + 1, 0);
+    for(int t = 1; t <= T; ++t)
+    {
+        cin >> Poses[t];
+        Poses[t] -= 1;
+    }
+
+    vector<vector<vector<int>>> DP(T + 1, vector(W + 1, vector(2, 0)));
+
+    for(int Walk = 0; Walk <= W; ++Walk)
+    {
+        for(int Time = 1; Time <= T; ++Time)
+        {
+            if(Time == 1)
+            {
+                DP[Time][Walk][0] = DP[Time - 1][Walk][0] + (Poses[Time] == 0);
+                if(Walk > 0)
+                {
+                    DP[Time][Walk][1] = DP[Time - 1][Walk - 1][0] + (Poses[Time] == 1);
+                }
+                continue;
+            }
+
+            if(Walk == 0)
+            {
+                DP[Time][Walk][0] = DP[Time - 1][Walk][0] + (Poses[Time] == 0);
+                DP[Time][Walk][1] = DP[Time - 1][Walk][1] + (Poses[Time] == 1);
+                continue;
+            }
+
+            DP[Time][Walk][0] = max(DP[Time - 1][Walk][0], DP[Time - 1][Walk - 1][1]) + (Poses[Time] == 0);
+            DP[Time][Walk][1] = max(DP[Time - 1][Walk - 1][0], DP[Time - 1][Walk][1]) + (Poses[Time] == 1);
+        }
+    }
+
+    int Ans = 0;
+    for(int Walk = 0; Walk <= W; ++Walk)
+    {
+        Ans = max({Ans, DP[T][Walk][0], DP[T][Walk][1]});
+    }
+    cout << Ans;
+
+    return 0;
+}

9-kyo-hwang/README.md

@@ -42,4 +42,7 @@
 | 39차시 | 2024.3.27  | Divide and Conquer         | [18291 비요뜨의 징검다리 건너기](https://www.acmicpc.net/problem/18291)        | [#150](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/150) |
 | 40차시 | 2024.4.2   | Dynamic Programming        | [7579 앱](https://www.acmicpc.net/problem/7579)        | [#153](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/153) |
 | 41차시 | 2024.4.7   | Prefix Sum                 | [2015 수들의 합 4](https://www.acmicpc.net/problem/2015)        | [#155](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/155) |
-| 42차시 | 2024.4.29  | Minimum Spanning Tree(MST) | [17472 다리 만들기 2](https://www.acmicpc.net/problem/17472)    | [#159](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/159) |
+| 42차시 | 2024.4.29  | Minimum Spanning Tree(MST) | [17472 다리 만들기 2](https://www.acmicpc.net/problem/17472)    | [#159](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/159) |
+| 43차시 | 2024.4.28  | Data Structure             | [3015 오아시스 재결합](https://www.acmicpc.net/problem/3015)    | [#162](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/162) |
+| 44차시 | 2024.5.6   | Backtracking               | [6987 월드컵](https://www.acmicpc.net/problem/6987)    | [#164](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/164) |
+| 45차시 | 2024.5.9   | Dynamic Programming        | [2240 자두나무](https://www.acmicpc.net/problem/2240)    | [#166](https://github.com/AlgoLeadMe/AlgoLeadMe-3/pull/166) |