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Diffstat (limited to 'aoc-2025/day7.asm')
| -rw-r--r-- | aoc-2025/day7.asm | 302 |
1 files changed, 0 insertions, 302 deletions
diff --git a/aoc-2025/day7.asm b/aoc-2025/day7.asm deleted file mode 100644 index 1d990a7..0000000 --- a/aoc-2025/day7.asm +++ /dev/null @@ -1,302 +0,0 @@ -; Advent of Code 2025 - Day 7 - -bits 64 -default rel - -global _start - -%include "utils/io.asm" - -%define RAW_SIZE 1048576 -%define MAX_W 1024 -%define MAX_H 1024 -%define GRID_SIZE (MAX_W * MAX_H) - -section .data - input_path db "input/day7.txt", 0 - - label1 db "Part 1: ", 0 - label2 db "Part 2: ", 0 - -section .bss - raw resb RAW_SIZE - grid resb GRID_SIZE ; height x width, '.'-filled - g resq (MAX_W * MAX_H) ; part 2 timeline counts - cur resb MAX_W ; part 1 active columns (this row) - nxt resb MAX_W ; part 1 active columns (next row) - - raw_len resq 1 - width resq 1 - height resq 1 - srow resq 1 - scol resq 1 - - part1 resq 1 - part2 resq 1 - -section .text - -_start: - mov rdi, input_path - lea rsi, [raw] - mov rdx, RAW_SIZE - call read_file - mov [raw_len], rax - - ; width = length of the first line - xor rcx, rcx -width_scan: - cmp rcx, [raw_len] - jge width_done - mov al, [raw + rcx] - cmp al, 10 - je width_done - cmp al, 13 - je width_done - inc rcx - jmp width_scan -width_done: - mov [width], rcx - - ; height = number of lines - xor rcx, rcx - xor r8, r8 -height_scan: - cmp rcx, [raw_len] - jge height_tail - mov al, [raw + rcx] - cmp al, 10 - jne height_next - inc r8 -height_next: - inc rcx - jmp height_scan -height_tail: - mov rax, [raw_len] - test rax, rax - jz height_store - mov dl, [raw + rax - 1] - cmp dl, 10 - je height_store - inc r8 -height_store: - mov [height], r8 - - ; '.'-fill the grid, then copy the raw bytes into it - mov rax, [height] - imul rax, [width] - mov rcx, rax - lea rdi, [grid] - mov al, '.' - rep stosb - - xor r8, r8 ; raw index - xor r9, r9 ; row - xor r10, r10 ; col -fill_loop: - cmp r8, [raw_len] - jge fill_done - mov al, [raw + r8] - inc r8 - cmp al, 10 - je fill_newline - cmp al, 13 - je fill_loop - cmp r10, [width] - jge fill_loop - mov rdx, r9 - imul rdx, [width] - add rdx, r10 - mov [grid + rdx], al - inc r10 - jmp fill_loop -fill_newline: - inc r9 - xor r10, r10 - jmp fill_loop -fill_done: - - ; locate S - xor r8, r8 - mov rax, [height] - imul rax, [width] - mov r9, rax -find_s: - cmp r8, r9 - jge s_done - mov al, [grid + r8] - cmp al, 'S' - je s_found - inc r8 - jmp find_s -s_found: - mov rax, r8 - xor rdx, rdx - div qword [width] - mov [srow], rax - mov [scol], rdx -s_done: - - ; part 1: flood a set of active columns, counting splitter hits - lea rdi, [cur] - mov rcx, MAX_W - xor al, al - rep stosb - mov rax, [scol] - mov byte [cur + rax], 1 - - xor r15, r15 ; row -p1_row: - cmp r15, [height] - jge p1_done - lea rdi, [nxt] - mov rcx, MAX_W - xor al, al - rep stosb - - mov rax, r15 - imul rax, [width] - mov r14, rax ; row offset - xor r13, r13 ; col - xor r12, r12 ; any beam alive? -p1_col: - cmp r13, [width] - jge p1_col_done - mov al, [cur + r13] - test al, al - jz p1_next - mov rdx, r14 - add rdx, r13 - mov al, [grid + rdx] - cmp al, '^' - jne p1_pass - inc qword [part1] - mov rbx, r13 ; left neighbor - test rbx, rbx - jz p1_no_left - dec rbx - mov byte [nxt + rbx], 1 - mov r12, 1 -p1_no_left: - mov rbx, r13 ; right neighbor - inc rbx - cmp rbx, [width] - jge p1_no_right - mov byte [nxt + rbx], 1 - mov r12, 1 -p1_no_right: - jmp p1_next -p1_pass: - mov byte [nxt + r13], 1 - mov r12, 1 -p1_next: - inc r13 - jmp p1_col -p1_col_done: - lea rsi, [nxt] - lea rdi, [cur] - mov rcx, MAX_W - rep movsb - test r12, r12 - jz p1_done - inc r15 - jmp p1_row -p1_done: - - ; part 2: bottom-up DP of timeline counts, g[r][c] - mov r15, [height] - dec r15 ; row, counting down -p2_row: - cmp r15, 0 - jl p2_done - mov rax, r15 - imul rax, [width] - mov r14, rax ; row offset - xor r13, r13 ; col -p2_col: - cmp r13, [width] - jge p2_col_done - mov rdx, r14 - add rdx, r13 ; idx = r*W + c - mov al, [grid + rdx] - cmp al, '^' - je p2_split - - ; pass straight down: g = (r+1 in grid ? g[r+1][c] : 1) - mov rbx, r15 - inc rbx - cmp rbx, [height] - jge p2_pass_exit - mov rcx, rdx - add rcx, [width] - mov rax, [g + rcx*8] - jmp p2_store -p2_pass_exit: - mov rax, 1 - jmp p2_store - -p2_split: - ; left child enters (r+1, c-1) - mov rbx, r15 - inc rbx - cmp rbx, [height] - jge p2_left_one - cmp r13, 0 - jle p2_left_one - mov rcx, rdx - add rcx, [width] - dec rcx - mov r8, [g + rcx*8] - jmp p2_left_done -p2_left_one: - mov r8, 1 -p2_left_done: - ; right child enters (r+1, c+1) - mov rbx, r15 - inc rbx - cmp rbx, [height] - jge p2_right_one - mov rbx, r13 - inc rbx - cmp rbx, [width] - jge p2_right_one - mov rcx, rdx - add rcx, [width] - inc rcx - mov r9, [g + rcx*8] - jmp p2_right_done -p2_right_one: - mov r9, 1 -p2_right_done: - mov rax, r8 - add rax, r9 -p2_store: - mov [g + rdx*8], rax - inc r13 - jmp p2_col -p2_col_done: - dec r15 - jmp p2_row -p2_done: - mov rax, [srow] - imul rax, [width] - add rax, [scol] - mov rax, [g + rax*8] - mov [part2], rax - -print_results: - mov rcx, label1 - call print_string - mov rax, [part1] - call print_int64 - call print_newline - - mov rcx, label2 - call print_string - mov rax, [part2] - call print_int64 - call print_newline - - mov rax, SYS_EXIT - xor rdi, rdi - syscall |