some programs!

cs101/dh_20260909_14_encryption.cpp

@@ -0,0 +1,90 @@
+#include <cstring>
+#include <iostream>
+#include <sstream>
+#include <vector>
+
+class Coord {
+public:
+    int x = 0, y = 0;
+    constexpr Coord(int x, int y) : x(x), y(y) {}
+
+    constexpr Coord operator+(const Coord other) const {
+        return {x + other.x, y + other.y};
+    }
+
+    constexpr Coord& operator+=(const Coord other) {
+        x += other.x, y += other.y;
+        return *this;
+    }
+
+    constexpr bool operator==(const Coord other) const {
+        return x == other.x && y == other.y;
+    }
+
+    friend std::ostream& operator<<(std::ostream& os, const Coord coord) {
+        return os << "(" << coord.x << ", " << coord.y << ")";
+    }
+};
+
+constexpr int MAX_N = 10;
+int w, h, grid[MAX_N][MAX_N];
+std::string original_str;
+
+std::vector<int> get_nums(const char c) {
+    if (c == ' ') { return {0, 0}; }
+    return {(c - 'A' + 1) / 10, (c - 'A' + 1) % 10};
+}
+
+Coord next_move(const Coord prev_coord, const Coord prev_facing) {
+    Coord new_coord = prev_coord + prev_facing;
+    if (new_coord.x < 0 || new_coord.x >= h ||
+        new_coord.y < 0 || new_coord.y >= w ||
+        grid[new_coord.x][new_coord.y] != -1) {
+        if (prev_facing == Coord{1, 0}) { return {0, -1}; }
+        if (prev_facing == Coord{0, -1}) { return {-1, 0}; }
+        if (prev_facing == Coord{-1, 0}) { return {0, 1}; }
+        if (prev_facing == Coord{0, 1}) { return {1, 0}; }
+        throw std::invalid_argument("Invalid facing direction");
+    }
+    return prev_facing;
+}
+
+std::ostream& print_grid(std::ostream& os) {
+    for (int i = 0; i < h; i++) {
+        for (int j = 0; j < w; j++) {
+            os << (grid[i][j] == -1 ? 0 : grid[i][j]);
+        }
+    }
+    os << std::endl;
+    return os;
+}
+
+void fill_grid(const std::string& s) {
+    memset(grid, -1, sizeof(grid));
+    Coord coord = {0, 0}, facing = {0, 1};
+    for (const char c : s) {
+        for (const int x : get_nums(c)) {
+            grid[coord.x][coord.y] = x;
+            std::clog << "Placing " << x << " at " << coord << std::endl;
+            print_grid(std::clog);
+            coord += facing = next_move(coord, facing);
+        }
+    }
+}
+
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+
+    getline(std::cin, original_str);
+    std::stringstream ss(original_str);
+    ss >> h >> w;
+    getline(std::cin, original_str);
+    fill_grid(original_str);
+
+    print_grid(std::cout);
+
+
+    return 0;
+}