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#include <ctype.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aocdailies.h"
#include "aocutils.h"
/* === aoc202406 =======================================================
Hmmm, I've done something like this already this year... on day 4
I need rcmap() moved to aocutils ... done; now it's called `linearize2d`
===================================================================== */
static bool validpos(unsigned s, int r, int c) {
if (r < 0) return false;
if (c < 0) return false;
if ((unsigned)r >= s - 1) return false;
if ((unsigned)c >= s - 1) return false;
return true;
}
static void rightturn(int *drow, int *dcol) {
if (*drow) { *dcol = -*drow; *drow = 0; }
else { *drow = *dcol; *dcol = 0; }
}
void aoc202406(char *data, size_t len) {
(void)len;
// assume data is well-formatted and has the same number of rows and columns
unsigned size = 1 + strchr(data, '\n') - data;
unsigned linear_pos = strchr(data, '^') - data;
int row_pos = (int)(linear_pos / size);
int col_pos = (int)(linear_pos % size);
int deltarow = -1, deltacol = 0;
//printf("character at [%u, %u] is '%c'\n", row_pos, col_pos, data[linearize2d(size, row_pos, col_pos)]);
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#include <ctype.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aocdailies.h"
#include "aocutils.h"
/* === aoc202406 =======================================================
Hmmm, I've done something like this already this year... on day 4
I need rcmap() moved to aocutils ... done; now it's called `linearize2d`
Part Two: brute force? It likely is faster than coming up with an algo
Let's go: save map, for every available position put in an obstacle,
loop around until some place is visited 4? times or area is exited
===================================================================== */
static bool validpos(unsigned s, int r, int c) {
if (r < 0) return false;
if (c < 0) return false;
if ((unsigned)r >= s - 1) return false;
if ((unsigned)c >= s - 1) return false;
return true;
}
static void rightturn(int *drow, int *dcol) {
if (*drow) { *dcol = -*drow; *drow = 0; }
else { *drow = *dcol; *dcol = 0; }
}
void aoc202406(char *data, size_t len) {
char *savedmap = malloc(len + 1);
strcpy(savedmap, data);
// assume data is well-formatted and has the same number of rows and columns
unsigned size = 1 + strchr(data, '\n') - data;
unsigned linear_pos = strchr(data, '^') - data;
int row_pos = (int)(linear_pos / size);
int col_pos = (int)(linear_pos % size);
int deltarow = -1, deltacol = 0;
//printf("character at [%u, %u] is '%c'\n", row_pos, col_pos, data[linearize2d(size, row_pos, col_pos)]);
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/*fallthrough*/
case 'X': row_pos += deltarow;
col_pos += deltacol;
break;
}
}
printf("The guard visits %u positions before leaving the area.\n", visited);
}
/* === aoc202405 =======================================================
===================================================================== */
static int ppcmp(unsigned a, unsigned b, unsigned (*r)[2], size_t nr) {
for (size_t k = 0; k < nr; k++) {
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/*fallthrough*/
case 'X': row_pos += deltarow;
col_pos += deltacol;
break;
}
}
printf("The guard visits %u positions before leaving the area.\n", visited);
// Part Two
free(savedmap);
}
/* === aoc202405 =======================================================
===================================================================== */
static int ppcmp(unsigned a, unsigned b, unsigned (*r)[2], size_t nr) {
for (size_t k = 0; k < nr; k++) {
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