From f3edd63be50dc6ab92f8f975c1ddec8c4ee56cf8 Mon Sep 17 00:00:00 2001
From: Peter <peterr.00000@gmail.com>
Date: Tue, 14 Dec 2021 12:43:49 +0800
Subject: [PATCH] Day 13 solutions

---
 13/13-1and2.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 13/13-1and2.c

diff --git a/13/13-1and2.c b/13/13-1and2.c
new file mode 100644
index 0000000..10d5b8f
--- /dev/null
+++ b/13/13-1and2.c
@@ -0,0 +1,149 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include "../check_alloc.h"
+
+typedef struct
+{
+    bool **space; // space[y][x]
+    int size_x;
+    int size_y;
+} GRID_SPACE;
+
+GRID_SPACE *new_space()
+{
+    GRID_SPACE *p_space = calloc(1, sizeof(GRID_SPACE));
+    CHECK_ALLOC(p_space);
+    p_space->space = calloc(1, sizeof(bool *));
+    CHECK_ALLOC(p_space->space);
+    p_space->space[0] = calloc(1, sizeof(bool));
+    CHECK_ALLOC(p_space->space[0]);
+    p_space->size_x = 1;
+    p_space->size_y = 1;
+    return p_space;
+}
+
+void expand_x(GRID_SPACE *space, int new_x)
+{
+    new_x += 2;
+    for (size_t i = 0; i < space->size_y; i++) //TODO:CHECK;
+    {
+        space->space[i] = realloc(space->space[i], new_x * sizeof(bool));
+        for (size_t j = space->size_x; j < new_x; j++)
+            space->space[i][j] = false; // RESET MEMORY
+        CHECK_ALLOC(space->space[i]);
+    }
+    space->size_x = new_x;
+}
+
+void expand_y(GRID_SPACE *space, int new_y)
+{
+    new_y++;
+    space->space = realloc(space->space, new_y * sizeof(bool *));
+    CHECK_ALLOC(space->space);
+    for (size_t i = space->size_y; i < new_y; i++)
+    {
+        space->space[i] = calloc(space->size_x, sizeof(bool));
+        CHECK_ALLOC(space->space[i]);
+    }
+    space->size_y = new_y;
+}
+
+void resize_space(GRID_SPACE *space, int new_x, int new_y)
+{
+    if (new_x > space->size_x)
+        expand_x(space, new_x);
+    if (new_y > space->size_y)
+        expand_y(space, new_y);
+}
+
+GRID_SPACE *read_space(FILE *p_file)
+{
+    int x, y;
+    GRID_SPACE *p_space = new_space();
+    CHECK_ALLOC(p_file);
+    while (fscanf(p_file, "%d,%d\n", &x, &y) == 2)
+    {
+        resize_space(p_space, x, y);
+        p_space->space[y][x] = true;
+        // printf("%d %d\n", x, y);
+    }
+    // printf("Size %d %d\n", p_space->size_x, p_space->size_y);
+    fscanf(p_file, "[^\n]\n"); // SKIP EMPTY LINE
+    return p_space;
+}
+
+void print_space(GRID_SPACE *space)
+{
+    for (size_t i = 0; i < space->size_y; i++)
+    {
+        for (size_t j = 0; j < space->size_x; j++)
+            putchar(space->space[i][j] ? '#' : '.');
+        putchar('\n');
+    }
+    putchar('\n');
+}
+
+int count_visible(GRID_SPACE *space)
+{
+    int count = 0;
+    for (size_t i = 0; i < space->size_y; i++)
+        for (size_t j = 0; j < space->size_x; j++)
+            if (space->space[i][j])
+                count++;
+    return count;
+}
+
+// fold
+void fold_x(GRID_SPACE *space, int x)
+{
+    for (int i = 0; i < space->size_y; i++)
+    {
+        for (int j = x; j < space->size_x; j++)
+            if (space->space[i][j])
+                space->space[i][2 * x - j] = true;
+    }
+    space->size_x = x;
+}
+
+void fold_y(GRID_SPACE *space, int y)
+{
+    for (int i = y; i < space->size_y; i++)
+    {
+        for (int j = 0; j < space->size_x; j++)
+            if (space->space[i][j])
+                space->space[2 * y - i][j] = true;
+    }
+    space->size_y = y;
+}
+
+void fold(GRID_SPACE *space, FILE *p_file)
+{
+    char axis;
+    int line;
+    bool first = true;
+    while (fscanf(p_file, "fold along %c=%d\n", &axis, &line) == 2)
+    {
+        if (axis == 'y')
+            fold_y(space, line);
+        else
+            fold_x(space, line);
+        if (first)
+        {
+            first = false;
+            printf("FIRST VISIBLE: %d\n", count_visible(space));
+        }
+    };
+}
+
+//
+
+int main(int argc, char const *argv[])
+{
+    FILE *p_file = fopen("input", "r");
+    GRID_SPACE *p_space = read_space(p_file);
+    fold(p_space, p_file);
+    print_space(p_space);
+    return 0;
+}