AtCoder Beginner Contest 395

https://atcoder.jp/contests/abc395

Signed-off-by: Frederick Chen <seventeen@ohdragonboi.cn>

atcoder/abc395/A_Strictly_Increasing.cpp

@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+#define lo long long
+#define INF INT_MAX
+#define LLM LONG_LONG_MAX
+#define endl "\n"
+
+using namespace std;
+/*
+    toothless. #17
+    @fredcss_dev
+*/
+
+int n, a[1000005], b[1000005];
+bool f[100000005];
+
+signed main()
+{
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+        b[i] = a[i];
+        if (!f[a[i]]) f[a[i]] = 1;
+        else {
+            cout << "No";
+            return 0;
+        }
+    }
+    sort(a + 1, a + 1 + n);
+    for (int i = 1; i <= n; i++) {
+        if (a[i] != b[i]) {
+            cout << "No";
+            return 0;
+        }
+    }
+    cout << "Yes";
+    return 0;
+}

atcoder/abc395/B_Make_Target.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+#define lo long long
+#define InF InT_MAX
+#define LLM LOnG_LOnG_MAX
+#define endl "\n"
+
+using namespace std;
+/*
+    toothless. #17
+    @fredcss_dev
+*/
+
+int n;
+
+void wczffl_503()
+{
+    vector<vector<char>> grid(n, vector<char>(n, '.'));
+    for (int i = 1; i <= n; ++i) {
+        int j = n + 1 - i;
+        if (i > j) continue;
+
+        char fillChar = (i % 2 == 1) ? '#' : '.';
+
+        for (int k = i - 1; k < j; ++k) {
+            for (int l = i - 1; l < j; ++l) {
+                grid[k][l] = fillChar;
+            }
+        }
+    }
+    for (int i = 0; i < n; ++i) {
+        for (int j = 0; j < n; ++j) {
+            cout << grid[i][j];
+        }
+        cout << endl;
+    }
+}
+
+signed main() {
+    cin >> n;
+    wczffl_503();
+    return 0;
+}

atcoder/abc395/C_Shortest_Duplicate_Subarray.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+#define lo long long
+#define INF INT_MAX
+#define LLM LONG_LONG_MAX
+#define endl "\n"
+
+using namespace std;
+/*
+    toothless. #17
+    @fredcss_dev
+*/
+
+int wczffl_503(int N, vector<int>& A) {
+    for (int i = 0; i < N - 1; ++i) {
+        if (A[i] == A[i + 1]) {
+            return 2;
+        }
+    }
+    unordered_map<int, vector<int>> pos;
+    for (int i = 0; i < N; ++i) {
+        pos[A[i]].push_back(i);
+    }
+    int mn = INT_MAX;
+    for (const auto& entry : pos) {
+        const vector<int>& vt = entry.second;
+        if (vt.size() < 2) continue;
+        
+        for (size_t i = 0; i < vt.size() - 1; ++i) {
+            int now = vt[i + 1] - vt[i] + 1;
+            if (now < mn) {
+                mn = now;
+            }
+        }
+    }
+    return (mn != INT_MAX) ? mn : -1;
+}
+
+int N;
+
+signed main() {
+    cin >> N;
+    vector<int> A(N);
+    for (int i = 0; i < N; ++i) {
+        cin >> A[i];
+    }
+    int res = wczffl_503(N, A);
+    cout << res;
+    return 0;
+}

atcoder/abc395/D_Pigeon_Swap(WA).cpp

@@ -0,0 +1,55 @@
+// 这个代码尚未正确，仅作参考价值
+
+#include <bits/stdc++.h>
+#define lo long long
+#define INF INT_MAX
+#define LLM LONG_LONG_MAX
+#define endl "\n"
+
+using namespace std;
+/*
+    toothless. #17
+    @fredcss_dev
+*/
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cout.tie(0);
+    int N, Q;
+    cin >> N >> Q;
+    vector<int> pigeon_to_nest(N + 1);
+    vector<unordered_set<int>> nest_to_pigeons(N + 1);
+    for (int i = 1; i <= N; ++i) {
+        pigeon_to_nest[i] = i;
+        nest_to_pigeons[i].insert(i);
+    }
+    for (int q = 0; q < Q; ++q) {
+        int type;
+        cin >> type;
+
+        if (type == 1) {
+            int a, b;
+            cin >> a >> b;
+            int current_nest = pigeon_to_nest[a];
+            nest_to_pigeons[current_nest].erase(a);
+            pigeon_to_nest[a] = b;
+            nest_to_pigeons[b].insert(a);
+        } else if (type == 2) {
+            int a, b;
+            cin >> a >> b;
+            swap(nest_to_pigeons[a], nest_to_pigeons[b]);
+            for (int pigeon : nest_to_pigeons[a]) {
+                pigeon_to_nest[pigeon] = a;
+            }
+            for (int pigeon : nest_to_pigeons[b]) {
+                pigeon_to_nest[pigeon] = b;
+            }
+        } else if (type == 3) {
+            int a;
+            cin >> a;
+            cout << pigeon_to_nest[a] << endl;
+        }
+    }
+    return 0;
+}