Add 'Week 4/D2 - 2'

Week 4/D2 - 2

@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+enum direction { // so up, etc can be used in functions, compile time constants
+    up = -10,
+    left = -1,
+    down = 10,
+    right = 1
+};
+
+int is_valid_dir(char *array, int index, int dir) {
+    switch (dir) {
+        case up:
+            return (index > 10 && *(array + index + dir) == '.');  // if pos isnt topmost, and above is .
+        case left:
+            return (index % 10 && *(array + index + dir) == '.'); // if pos isn't leftmost, and left isn't "."
+        case down:
+            return (index < 90 && *(array + index + 10) == '.'); //if pos isn't downmost, and down isn't "."
+        case right:
+            return (index % 10 != 9 && *(array + index + dir) == '.');
+        default:
+            return false;
+    }
+}
+
+bool is_stuck(char *arr, int index) {
+    return !(*(arr + index + up) == '.' ||
+             *(arr + index + down) == '.' ||
+             *(arr + index + left) == '.' ||
+             *(arr + index + right) == '.'
+    );
+}
+
+int main() {
+    srand(time(0)); // seed rand
+    int direction[4] = {-10, -1, 10, 1}; // to convert rand output to a position change
+    // generate maze
+    char maze_[10][10] = {};
+
+    for (int i = 0; i < 10; i++) { // the 2d way
+        for (int j = 0; j < 10; j++) {
+            maze_[i][j] = '.';
+        }
+    }
+    char *maze = &maze_;
+    char character = 'A';
+    int pos = 0;
+    maze[pos] = character;
+    // traverse maze
+    for (int i = 0; i < 25; i++) {
+        int dir = direction[rand() % 4];
+        while (!is_valid_dir(maze, pos, dir) && !is_stuck(maze, pos)) {
+            dir = direction[rand() % 4];
+        }
+        if (is_stuck(maze, pos)) {
+            printf("Got myself in a sticky situation\n");
+            break;
+        }
+        pos += dir;
+        maze[pos] = ++character;
+    }
+    for (int i = 0; i < 100; i++) {
+        printf("%c", maze[i]);
+        if (i % 10 == 9) {
+            printf("\n");
+        }
+    }
+}