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Diffstat (limited to 'aoc-2025/day6.asm')
| -rw-r--r-- | aoc-2025/day6.asm | 331 |
1 files changed, 0 insertions, 331 deletions
diff --git a/aoc-2025/day6.asm b/aoc-2025/day6.asm deleted file mode 100644 index 728b8b0..0000000 --- a/aoc-2025/day6.asm +++ /dev/null @@ -1,331 +0,0 @@ -; Advent of Code 2025 - Day 6 - -bits 64 -default rel - -global _start - -%include "utils/io.asm" - -%define RAW_SIZE 1048576 -%define MAX_W 8192 -%define MAX_H 64 -%define GRID_SIZE (MAX_W * MAX_H) - -section .data - input_path db "input/day6.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, space-filled - - raw_len resq 1 - width resq 1 - height resq 1 - - blk_c0 resq 1 ; current block: columns [blk_c0, blk_c1) - blk_c1 resq 1 - op resq 1 ; 0 = add, 1 = mul, -1 = none - - 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 (newlines, plus one if the last line has no newline) - 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 - - ; space-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: - - ; walk the columns, carving out blocks between all-space separators - xor r15, r15 ; column cursor -block_scan: - cmp r15, [width] - jge blocks_done - mov rdi, r15 - call col_is_sep - test rax, rax - jnz block_sep - mov [blk_c0], r15 -block_extend: - cmp r15, [width] - jge block_end - mov rdi, r15 - call col_is_sep - test rax, rax - jnz block_end - inc r15 - jmp block_extend -block_end: - mov [blk_c1], r15 - call process_block - jmp block_scan -block_sep: - inc r15 - jmp block_scan -blocks_done: - -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 - -; col_is_sep: is every row of column RDI a space? -; Output: RAX = 1 if the column is a separator, else 0 -; Clobbers: RAX, RDX, R8 -col_is_sep: - xor r8, r8 -.loop: - cmp r8, [height] - jge .sep - mov rax, r8 - imul rax, [width] - add rax, rdi - movzx edx, byte [grid + rax] - cmp dl, ' ' - jne .not - inc r8 - jmp .loop -.sep: - mov rax, 1 - ret -.not: - xor rax, rax - ret - -; process_block: fold the block [blk_c0, blk_c1) for both parts. -; Part 1 reads each row as a number; part 2 reads each column as a number. -; The bottom row supplies the operator. Clobbers RAX, RCX, RDX, R8-R14. -process_block: - ; find the operator on the bottom row within the block - mov rax, [height] - dec rax - imul rax, [width] - mov r11, rax ; offset of the operator row - mov qword [op], -1 - mov rcx, [blk_c0] -.find_op: - cmp rcx, [blk_c1] - jge .op_done - mov rdx, r11 - add rdx, rcx - mov al, [grid + rdx] - cmp al, '+' - je .set_add - cmp al, '*' - je .set_mul - inc rcx - jmp .find_op -.set_add: - mov qword [op], 0 - jmp .op_done -.set_mul: - mov qword [op], 1 -.op_done: - cmp qword [op], 0 - jl .ret ; no operator -> not a real problem - - ; part 1: one number per row - mov r12, [op] - xor r13, r13 ; accumulator - test r12, r12 - jz .p1_acc - mov r13, 1 -.p1_acc: - xor r14, r14 ; count of numbers folded - xor r10, r10 ; row -.p1_rows: - mov rax, [height] - dec rax - cmp r10, rax - jge .p1_done - mov rax, r10 - imul rax, [width] - mov r11, rax ; row offset - xor r8, r8 ; number - xor r9, r9 ; saw a digit? - mov rcx, [blk_c0] -.p1_cols: - cmp rcx, [blk_c1] - jge .p1_fold - mov rdx, r11 - add rdx, rcx - movzx eax, byte [grid + rdx] - cmp al, '0' - jl .p1_col_next - cmp al, '9' - jg .p1_col_next - sub al, '0' - movzx rax, al - imul r8, r8, 10 - add r8, rax - mov r9, 1 -.p1_col_next: - inc rcx - jmp .p1_cols -.p1_fold: - test r9, r9 - jz .p1_row_next - test r12, r12 - jnz .p1_mul - add r13, r8 - jmp .p1_counted -.p1_mul: - imul r13, r8 -.p1_counted: - inc r14 -.p1_row_next: - inc r10 - jmp .p1_rows -.p1_done: - test r14, r14 - jz .p2 - add [part1], r13 - - ; part 2: one number per column -.p2: - mov r12, [op] - xor r13, r13 - test r12, r12 - jz .p2_acc - mov r13, 1 -.p2_acc: - xor r14, r14 - mov rcx, [blk_c0] ; column -.p2_cols: - cmp rcx, [blk_c1] - jge .p2_done - xor r8, r8 ; number - xor r9, r9 ; saw a digit? - xor r10, r10 ; row -.p2_rows: - mov rax, [height] - dec rax - cmp r10, rax - jge .p2_fold - mov rax, r10 - imul rax, [width] - add rax, rcx - movzx edx, byte [grid + rax] - cmp dl, '0' - jl .p2_row_next - cmp dl, '9' - jg .p2_row_next - sub dl, '0' - movzx rdx, dl - imul r8, r8, 10 - add r8, rdx - mov r9, 1 -.p2_row_next: - inc r10 - jmp .p2_rows -.p2_fold: - test r9, r9 - jz .p2_col_next - test r12, r12 - jnz .p2_mul - add r13, r8 - jmp .p2_counted -.p2_mul: - imul r13, r8 -.p2_counted: - inc r14 -.p2_col_next: - inc rcx - jmp .p2_cols -.p2_done: - test r14, r14 - jz .ret - add [part2], r13 -.ret: - ret |