Advent of Code Leaderboard 2024 / Day 6

Submit solution

Leaderboard

	Name	Language	Tokens Sum	Tokens Part 1	Tokens Part 2	Last change
1	CornerMercury	Python	269	102	167	11 months ago
2	dbasden	C	561	251	310	11 months ago
3	Szabolcs Dombi	Python	10141	141	-	11 months ago
4	Mechazawa	JavaScript	10206	206	-	10 months ago
5	Tomáš Mach	Python	10234	234	-	11 months ago

Rules

You're welcome to participate alone or in a team.
You may submit multiple solutions and explore different programming languages.
Stick to the standard library of your language, no further dependencies/libraries, except the ones which OneCompiler provides (e.g. NumPy for Python).
Ensure your code aligns to the template (Python, Rust, Go, Kotlin, JavaScript, C#, TypeScript, C++, Java, C, Swift, Scala, Ruby, Bash), reading the puzzle input from stdin (terminated with end-of-file), and printing the solution to stdout.
Please refrain from making network requests, reading data from files, or storing data in variable/function/class names for reflection.
Your code must be able to process all valid Advent of Code inputs. Golfcoder might reevaluate correctness of your solution with different inputs after your submission.

310 tokens in C for part 2 by dbasden

Download solution

#include<stdio.h>

typedefstruct{
inti;
intj;
}pos_t;

#defineELFOFF

[elf_pos.i][elf_pos.j]
#definegijgrid[i][j]
chargrid[256][256];
intwidth,part_2_result,i,j;
pos_telf_start_pos,oob;

intevi[4]={-1,0,1},evj[4]={0,1,0,-1};

intdoes_guard_loop(){
intvec_idx=0;
intvisited[256][256][4]={};
pos_telf_pos=elf_start_pos;

while(gridELFOFF){
if(visitedELFOFF[vec_idx])return1;
visitedELFOFF[vec_idx]=1;
pos_tforward=(pos_t){elf_pos.i+evi[vec_idx],elf_pos.j+evj[vec_idx]};
if(grid[forward.i][forward.j]!=35&&!(forward.i==i&&forward.j==j))
elf_pos=forward;
elsevec_idx=(vec_idx+1)&3;
}
return0;
}

intmain(){
while(scanf("%s%n",&(grid[++i][0]),&width)==1)
for(j=0;j<width;++j)
if(gij==94)elf_start_pos=(pos_t){i,j};
for(i=1;i<width;++i)
for(j=0;j<width;++j)
part_2_result+=gij!=94&&does_guard_loop();
printf("%d\n",part_2_result);
}