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#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include "util.h"
s32 reduce(s32 (*f)(s32 x, s32 y), s32 arr[], s32 len)
{
s32 ret = arr[0];
for (s32 i = 1; i < len; ++i) {
ret = f(ret, arr[i]);
}
return ret;
}
s32 mul(s32 x, s32 y)
{
return x * y;
}
s32 max(s32 x, s32 y)
{
return x > y ? x : y;
}
s32 count_char_in_string(char c, char *s)
{
s32 count = 0;
do
if (c == *s)
count++;
while (*s++);
return count;
}
char *goto_char_in_string(char c, char *s)
{
do
if (c == *s)
return s;
while (*s++);
return NULL;
}
#define PP(arr, y,x) *(*(arr+y)+x)
// char filename[] = "in/day08.ref";
char filename[] = "in/day08.pzl";
#define BUF_LEN 10000
char file_buf[BUF_LEN];
int main()
{
int fd = open(filename, O_RDONLY);
s32 data_len = read(fd, file_buf, LEN(file_buf));
if (data_len == -1) {
printf("error opening file\n");
exit(1);
} else if (data_len == LEN(file_buf)) {
printf("buffer probably not big enough\n");
exit(1);
}
file_buf[data_len] = '\0';
s32 y_len = count_char_in_string('\n', file_buf);
s32 x_len;
// printf("y_len: %d\n", y_len);
s32 **arr = malloc(y_len * sizeof(s32*));
s32 **flag = malloc(y_len * sizeof(s32*));
char *start = file_buf;
for (s32 i = 0; i < y_len; ++i) {
char *end = goto_char_in_string('\n', start);
x_len = end - start;
// printf("x_len: %d\n", x_len);
*(arr+i) = malloc(x_len * sizeof(s32*));
*(flag+i) = malloc(x_len * sizeof(s32*));
for (s32 j = 0; j < x_len; ++j) {
*(*(arr+i) + j) = *(start + j) - '0';
*(*(flag+i) + j) = 0;
}
start = end+1;
}
s32 res1 = 0;
s32 maxval;
#define RES1_CHECK() \
if (PP(arr, y, x) > maxval) { \
maxval = PP(arr, y, x); \
if (PP(flag, y, x) == 0) { \
PP(flag, y, x) = 1; \
res1 += 1; \
} \
}
for (s32 y = 0; y < y_len; ++y) {
maxval = -1;
for (s32 x = 0; x < x_len; ++x)
RES1_CHECK();
maxval = -1;
for (s32 x = x_len-1; x >= 0 ; --x)
RES1_CHECK();
}
for (s32 x = 0; x < x_len; ++x) {
maxval = -1;
for (s32 y = 0; y < y_len; ++y)
RES1_CHECK();
maxval = -1;
for (s32 y = y_len-1; y >= 0 ; --y)
RES1_CHECK();
}
s32 res2 = 0;
for (s32 y = 0; y < y_len; ++y) {
for (s32 x = 0; x < x_len; ++x) {
s32 rldu[4] = {0};
for (s32 r = x+1; r < x_len; ++r)
if ((PP(arr,y,r) >= PP(arr,y,x)) || (r==(x_len-1))) {
rldu[0] += r-x;
break;
}
for (s32 l = x-1; l >= 0; --l)
if ((PP(arr,y,l) >= PP(arr,y,x)) || (l==0)) {
rldu[1] += x-l;
break;
}
for (s32 d = y+1; d < y_len; ++d)
if ((PP(arr,d,x) >= PP(arr,y,x)) || (d==(y_len-1))) {
rldu[2] += d-y;
break;
}
for (s32 u = y-1; u >= 0; --u)
if ((PP(arr,u,x) >= PP(arr,y,x)) || (u==0)) {
rldu[3] += y-u;
break;
}
res2 = max(res2, reduce(mul, rldu, LEN(rldu)));
}
}
printf("res1: %d\n", res1);
printf("res2: %d\n", res2);
// asm("int3");
}
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