Merge branch 'main' of github.com:tkzzzzzz6/Algorithm_beginner_learning_notes

Author: ttkqwe123

CCF-CSP/CSP202104B. 邻域均值.cpp

@@ -0,0 +1,57 @@
+/*
+ * @Author: tkzzzzzz6
+ * @Date: 2026-05-27 08:59:09
+ * @LastEditors: tkzzzzzz6
+ * @LastEditTime: 2026-05-27 10:04:32
+ */
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#define endl '\n'
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cout.tie(0);
+
+    int n, L, r, t;
+    cin >> n >> L >> r >> t;
+
+    vector<vector<int>> A(n, vector<int>(n));
+    for (int i = 0; i < n; ++i)
+        for (int j = 0; j < n; ++j)
+            cin >> A[i][j];
+
+    vector<vector<long long>> sum(n, vector<long long>(n));
+    for (int i = 0; i < n; ++i)
+        for (int j = 0; j < n; ++j) {
+            sum[i][j] += A[i][j];
+            if (i > 0) sum[i][j] += sum[i - 1][j];
+            if (j > 0) sum[i][j] += sum[i][j - 1];
+            if (i > 0 && j > 0) sum[i][j] -= sum[i - 1][j - 1];
+        }
+
+    auto query = [&](int x1, int y1, int x2, int y2) -> long long {
+        long long res = sum[x2][y2];
+        if (x1 > 0) res -= sum[x1 - 1][y2];
+        if (y1 > 0) res -= sum[x2][y1 - 1];
+        if (x1 > 0 && y1 > 0) res += sum[x1 - 1][y1 - 1];
+        return res;
+    };
+
+    int ans = 0;
+    for (int i = 0; i < n; ++i) {
+        for (int j = 0; j < n; ++j) {
+            int x1 = max(0, i - r), y1 = max(0, j - r);
+            int x2 = min(n - 1, i + r), y2 = min(n - 1, j + r);
+            long long s = query(x1, y1, x2, y2);
+            int m = (x2 - x1 + 1) * (y2 - y1 + 1);
+            if (s <= 1LL * t * m) ans++;
+        }
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}

CCF-CSP/CSP202512B. 数字变换.cpp

@@ -0,0 +1,56 @@
+/*
+ * @Author: tkzzzzzz6
+ * @Date: 2026-05-26 18:59:16
+ * @LastEditors: tkzzzzzz6
+ * @LastEditTime: 2026-05-26 19:08:36
+ */
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+inline int f(int x, int k) {
+    return ((x * x + k * k) % 8) ^ k;
+}
+
+inline int g(int x, int k) {
+    int a = (x >> 6) & 7;
+    int b = (x >> 3) & 7;
+    int c = x & 7;
+
+    int na = b;
+    int nb = c ^ f(b, k);
+    int nc = a ^ f(c, k);
+
+    return na << 6 | nb << 3 | nc;
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+    cin >> n >> m;
+    vector<int> k(m);
+    for (int i = 0; i < m; ++i) cin >> k[i];
+
+    vector<int> rev(512);
+    for (int i = 0; i < 512; ++i) {
+        int x = i;
+        for (int j = 0; j < m; ++j) {
+            x = g(x, k[j]);
+        }
+        rev[x] = i;
+    }
+
+    for (int i = 0; i < n; ++i) {
+        int a;
+        cin >> a;
+        cout << rev[a];
+        if (i + 1 < n) cout << ' ';
+    }
+
+    cout << '\n';
+
+    return 0;
+}