Big Bang

1 files changed, 154 insertions, 0 deletions

diff --git a/Advent-of-Code-2021/AOC-25/aoc-25.c b/Advent-of-Code-2021/AOC-25/aoc-25.c
new file mode 100644
index 0000000..089b141
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-25/aoc-25.c
@@ -0,0 +1,154 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <math.h>
+#include <stdint.h>
+
+#define XLEN 139 //10
+#define YLEN 137 //9
+#define LEN (XLEN * YLEN)
+
+typedef struct Sea_cuc_move {
+  int from_pos;
+  int to_pos;
+} Sea_cuc_move;
+
+char map[LEN];
+char map_bak[LEN];
+
+void ParseInput(char *filepath)
+{
+  char ch;
+  FILE *fp;
+  fp = fopen(filepath, "r");
+
+  if(fp == NULL)
+  {
+    fprintf(stderr, "ERROR: something with file idk what fuck you");
+    exit(EXIT_FAILURE);
+  }
+
+  int i = 0;
+  while((ch = fgetc(fp)) != EOF)
+  {
+    if(ch == '\n') continue;
+
+    map[i] = ch;
+    i++;
+  }
+
+  fclose(fp);
+}
+
+void Move(char type, Sea_cuc_move pos)
+{
+  map[pos.from_pos] = '.';
+  map[pos.to_pos] = type;
+}
+
+void MoveEast()
+{
+  Sea_cuc_move positions_east[5000];
+  int cucs_east = 0;
+  
+  for(int i=0; i<LEN; i++)
+  {
+    if(map[i] == '>')
+    {
+      int x = i % XLEN;
+      if(x == (XLEN-1))
+      {
+	if(map[i - x] != '.')
+	  continue;
+	
+	positions_east[cucs_east] = (Sea_cuc_move){i, i - x};
+	cucs_east += 1;
+      }
+      else if(map[i+1] == '.')
+      {
+	positions_east[cucs_east] = (Sea_cuc_move){i, i + 1};
+	cucs_east += 1;
+      }
+	
+    }
+  }
+
+  assert(cucs_east  < 5000);
+
+  if(cucs_east != 0)
+    for(int i=0; i<cucs_east; i++)
+      Move('>', positions_east[i]);
+}
+
+void MoveSouth()
+{
+  Sea_cuc_move positions_south[5000];
+  int cucs_south = 0;
+  
+  for(int i=0; i<LEN; i++)
+  {
+    if(map[i] == 'v')
+    {
+      int y = floor(i / XLEN);
+      if(y == (YLEN-1))
+      {
+	if(map[i%XLEN] != '.')
+	   continue;
+
+        positions_south[cucs_south] = (Sea_cuc_move){i, i%XLEN};
+        cucs_south += 1;	
+      }
+      else if (map[i+XLEN] == '.')
+      {
+	positions_south[cucs_south] = (Sea_cuc_move){i, i+XLEN};
+        cucs_south +=1;
+      }
+    }
+  }
+
+  assert(cucs_south < 5000);
+  
+  if(cucs_south != 0)
+    for(int i=0; i<cucs_south; i++)
+      Move('v', positions_south[i]);
+}
+
+void NextStep()
+{
+  MoveEast();
+  MoveSouth();
+}
+
+void PrintMap()
+{
+  for(int i=0; i<LEN; i++)
+  {
+    if((i % XLEN) == 0)
+      printf("\n");
+    printf("%c", map[i]);
+  }
+  printf("\n\n");
+}
+    
+		
+int main()
+{  
+  ParseInput("input.txt");
+
+  for(u_int64_t i=0; i < 10000; i++)
+  {
+    memcpy(map_bak, map, sizeof(char) * LEN);
+    NextStep();
+    
+    if(strcmp(map, map_bak) == 0)
+    {
+      printf("EQUAL after: %llu\n", i + 1);
+      exit(0);
+    }
+  }
+
+  PrintMap();
+  
+  return 0;
+}