From 2b0dad9d87b2b663ddc008876a4dbc3d17993d27 Mon Sep 17 00:00:00 2001 From: hachem Date: Tue, 25 Aug 2026 11:26:54 +0200 Subject: chore: refactor repository --- aoc-2025/day1.asm | 314 +++++++++++++++++++++++++++++++++++++++++ aoc-2025/day2.asm | 410 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ aoc-2025/day3.asm | 301 +++++++++++++++++++++++++++++++++++++++ aoc-2025/day4.asm | 25 ++++ 4 files changed, 1050 insertions(+) create mode 100644 aoc-2025/day1.asm create mode 100644 aoc-2025/day2.asm create mode 100644 aoc-2025/day3.asm create mode 100644 aoc-2025/day4.asm (limited to 'aoc-2025') diff --git a/aoc-2025/day1.asm b/aoc-2025/day1.asm new file mode 100644 index 0000000..8ba8f0e --- /dev/null +++ b/aoc-2025/day1.asm @@ -0,0 +1,314 @@ +; Advent of Code 2025 - Day 1 + +bits 64 +default rel + +global _start + +%define SYS_EXIT 60 +%define SYS_READ 0 +%define SYS_WRITE 1 +%define SYS_OPEN 2 +%define SYS_CLOSE 3 + +%define O_RDONLY 0 +%define STDOUT 1 + +section .data + inputPath db "input/day1.txt", 0 + newline db 10 + + label1 db "Password 1: ", 0 + label2 db "Password 2: ", 0 + + angle1 dd 50 + angle2 dd 50 + + password1 dd 0 + password2 dd 0 + +section .bss + buffer resb 4096 + lineBuffer resb 256 + numberBuffer resb 16 + lineLen resd 1 + +section .text + +_start: + ; open file + mov rax, SYS_OPEN + mov rdi, inputPath + mov rsi, O_RDONLY + xor rdx, rdx + syscall + + mov r12, rax ; fd in R12 + mov dword [lineLen], 0 ; no chars in current line yet + +ReadLoop: + ; read up to 4096 bytes + mov rax, SYS_READ + mov rdi, r12 + mov rsi, buffer + mov rdx, 4096 + syscall + + cmp rax, 0 + jle EOF ; <=0 -> EOF or error + + mov rdi, buffer ; scan pointer + mov rbp, rax ; bytes remaining in this chunk + +ScanChunk: + cmp rbp, 0 + je ReadLoop ; chunk done, read next + + mov al, [rdi] + + ; windows can be a fucking bitch + ; handle (CR) -> just skip + cmp al, 13 + je SkipCR + + ; handle LF (10) -> end of line + cmp al, 10 + je EndOfLine + + ; normal character -> append to lineBuffer if space left + mov edx, [lineLen] + cmp edx, 255 ; leave 1 byte for NULL + jae SkipStore ; ignore extra characters if too long + mov [lineBuffer+rdx], al + inc edx + mov [lineLen], edx + +SkipStore: + inc rdi + dec rbp + jmp ScanChunk + +SkipCR: + inc rdi + dec rbp + jmp ScanChunk + +EndOfLine: + ; terminate current line + mov edx, [lineLen] + mov byte [lineBuffer+rdx], 0 + + ; if line isn't empty, process it + cmp edx, 0 + je LineDone + + push rdi + mov rsi, lineBuffer + call HandleLine + pop rdi + +LineDone: + mov dword [lineLen], 0 ; reset line length + inc rdi + dec rbp + jmp ScanChunk + +; process last line if not newline-terminated, then print result +EOF: + ; if there is a partial line at EOF, process it + mov edx, [lineLen] + cmp edx, 0 + jle PrintResults + mov byte [lineBuffer+rdx], 0 + + mov rsi, lineBuffer + call HandleLine + +PrintResults: + mov rcx, label1 + call PrintString + mov eax, [password1] + call PrintInt + + ; newline + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, newline + mov rdx, 1 + syscall + + mov rcx, label2 + call PrintString + mov eax, [password2] + call PrintInt + + ; new linhe + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, newline + mov rdx, 1 + syscall + + mov rax, SYS_CLOSE + mov rdi, r12 + syscall + mov rax, SYS_EXIT + xor rdi, rdi + syscall + +; Handle one line: RSI -> "L123" or "R45" +HandleLine: + mov al, [rsi] + cmp al, 'L' + je .left + mov ebx, 1 ; direction = +1 for 'R' or anything else + jmp .after +.left: + mov ebx, -1 ; direction = -1 for 'L' +.after: + inc rsi ; skip 'L' or 'R' + call ParseInt ; EAX = steps + mov ecx, eax + +; Part 1 +P1_Start: + mov eax, ecx + imul eax, ebx + add eax, [angle1] + call NormalizeAngle + mov [angle1], eax + cmp eax, 0 + jne P2_Start + mov rdi, password1 + mov edx, [rdi] + inc edx + mov [rdi], edx + +; Part 2 +P2_Start: + mov rdi, password2 +.loop: + test ecx, ecx + jle P2_Exit + dec ecx + + mov eax, [angle2] + call UpdateAngleCount + mov [angle2], eax + + jmp .loop +P2_Exit: + ret + +; normalize eax to 0..99 +NormalizeAngle: + cmp eax, 0 + jl .add + cmp eax, 100 + jl .done + sub eax, 100 + jmp NormalizeAngle +.add: + add eax, 100 + jmp NormalizeAngle +.done: + ret + +; eax = angle, ebx = direction, rdi = password counter addr +UpdateAngleCount: + add eax, ebx + call NormalizeAngle + + cmp eax, 0 + jne .done + mov edx, [rdi] + inc edx + mov [rdi], edx +.done: + ret + +; parse ASCII integer into EAX +ParseInt: + xor eax, eax ; result = 0 +.parseLoop: + mov dl, [rsi] + cmp dl, '0' + jl .done + cmp dl, '9' + jg .done + + sub dl, '0' ; digit value 0..9 + movzx edx, dl + + imul eax, eax, 10 ; result *= 10 + add eax, edx ; result += digit + + inc rsi + jmp .parseLoop +.done: + ret + +PrintInt: + mov edi, numberBuffer+15 ; write digits from the end + mov byte [rdi], 0 ; terminator + dec rdi + + cmp eax, 0 + jne .convert + mov byte [rdi], '0' + jmp .finish +.convert: + ; we will repeatedly compute: + ; q = eax / 10 + ; r = eax % 10 + ; using only subtraction +.nextDigit: + mov edx, eax ; tmp = current value + mov ecx, 0 ; q = 0 + + cmp edx, 10 ; if < 0, q=0, r=edx + jb .lastDigit +.subLoop: + sub edx, 10 + inc ecx ; q++ + cmp edx, 10 + jae .subLoop ; while tmp >= 10 +.lastDigit: + ; now: + ; ecx = quotient + ; edx = remainder (0..9) + add dl, '0' + mov [rdi], dl ; store digit + dec rdi + mov eax, ecx ; eax = quotient + test eax, eax + jnz .nextDigit ; more digits to extract? + + inc rdi ; move to first digit +.finish: + mov rax, SYS_WRITE + mov rsi, rdi ; buffer pointer + mov rdi, STDOUT + mov rdx, numberBuffer+15 + sub rdx, rsi ; length + syscall + ret + +PrintString: + push rcx + push rdx + mov rdx, 0 +.count: + cmp byte [rcx+rdx], 0 + je .doneCount + inc rdx + jmp .count +.doneCount: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, rcx + syscall + + pop rdx + pop rcx + ret diff --git a/aoc-2025/day2.asm b/aoc-2025/day2.asm new file mode 100644 index 0000000..dfbfb38 --- /dev/null +++ b/aoc-2025/day2.asm @@ -0,0 +1,410 @@ +; Advent of Code 2025 – Day 2 + +bits 64 +default rel + +global _start + +%define SYS_EXIT 60 +%define SYS_READ 0 +%define SYS_WRITE 1 +%define SYS_OPEN 2 +%define SYS_CLOSE 3 + +%define O_RDONLY 0 +%define STDOUT 1 + +section .data + inputPath db "input/day2.txt", 0 + newline db 10 + + label1 db "Part 1: ", 0 + label2 db "Part 2: ", 0 + +section .bss + buffer resb 4096 + lineBuffer resb 65536 + lineLen resd 1 + + sum1 resq 1 + sum2 resq 1 + + numberBuffer resb 32 ; for printing and NumberToString + +section .text + +_start: + mov rax, SYS_OPEN + mov rdi, inputPath + mov rsi, O_RDONLY + xor rdx, rdx + syscall + + mov r12, rax ; file descriptor + mov dword [lineLen], 0 + +ReadLoop: + mov rax, SYS_READ + mov rdi, r12 + mov rsi, buffer + mov rdx, 4096 + syscall + + cmp rax, 0 + jle EOF + + mov rdi, buffer + mov rbp, rax + +ScanChunk: + cmp rbp, 0 + je ReadLoop + + mov al, [rdi] + + cmp al, 13 + je SkipCR + + cmp al, 10 + je EndLine + + mov edx, [lineLen] + cmp edx, 65535 + jae SkipStore + mov [lineBuffer+rdx], al + inc edx + mov [lineLen], edx + +SkipStore: + inc rdi + dec rbp + jmp ScanChunk + +SkipCR: + inc rdi + dec rbp + jmp ScanChunk + +EndLine: + mov edx, [lineLen] + mov byte [lineBuffer+rdx], 0 + + cmp edx, 0 + je ClearLine + + push rdi + mov rsi, lineBuffer + call HandleLine + pop rdi + +ClearLine: + mov dword [lineLen], 0 + inc rdi + dec rbp + jmp ScanChunk + +EOF: + ; process final partial line if needed + mov edx, [lineLen] + cmp edx, 0 + jle PrintResults + + mov byte [lineBuffer+rdx], 0 + mov rsi, lineBuffer + call HandleLine + +PrintResults: + mov rcx, label1 + call PrintString + mov rax, [sum1] + call PrintInt64 + call Newline + + mov rcx, label2 + call PrintString + mov rax, [sum2] + call PrintInt64 + call Newline + + mov rax, SYS_CLOSE + mov rdi, r12 + syscall + + mov rax, SYS_EXIT + xor rdi, rdi + syscall + +; parse "A-B,C-D,..."l, RSI = pointer to line +; uses r13 = current ID, r14 = end of range +HandleLine: +NextRange: + ; parse start + call ParseInt64 + mov r13, rax + + cmp byte [rsi], '-' + jne DoneLine + inc rsi + + ; parse end + call ParseInt64 + mov r14, rax + +RangeLoop: + cmp r13, r14 + jg AfterRange + + ; Save RSI (line pointer) across the checks, + ; because NumberToString / CheckInvalid* use RSI + push rsi + + ; Part 1: exact AA + mov rax, r13 + call CheckInvalid1 + test rax, rax + jz .skipP1 + add qword [sum1], r13 +.skipP1: + ; Part 2: any repeating block >= 2 + mov rax, r13 + call CheckInvalid2 + test rax, rax + jz .skipP2 + add qword [sum2], r13 +.skipP2: + pop rsi ; restore line pointer + + inc r13 + jmp RangeLoop + +AfterRange: + cmp byte [rsi], ',' + jne DoneLine + inc rsi + jmp NextRange + +DoneLine: + ret + +; RSI points at decimal digits; stops on first non-digit +ParseInt64: + xor rax, rax +.parse: + mov dl, [rsi] + cmp dl, '0' + jl .done + cmp dl, '9' + jg .done + + sub dl, '0' + movzx rdx, dl + imul rax, rax, 10 + add rax, rdx + + inc rsi + jmp .parse +.done: + ret + +; NumberToString: convert RAX to decimal ASCII, MSB-first +; Output: +; RSI = pointer to first digit +; ECX = length +NumberToString: + mov rdi, numberBuffer+31 + mov byte [rdi], 0 ; terminator (for convenience) + dec rdi + + cmp rax, 0 + jne .conv + + ; handle zero + mov byte [rdi], '0' + mov rsi, rdi + mov ecx, 1 + ret + +.conv: + mov rbx, 10 +.nextDigit: + xor rdx, rdx + div rbx ; RAX = quotient, RDX = remainder + add dl, '0' + mov [rdi], dl + dec rdi + test rax, rax + jnz .nextDigit + + inc rdi ; now RDI points to first digit + mov rsi, rdi + mov rdx, numberBuffer+31 + sub rdx, rsi ; RDX = length + mov ecx, edx + ret + +; CheckInvalid1: "AA" pattern +; RAX = number +; Returns RAX = 1 if digits == A A, else 0 +CheckInvalid1: + push rbx + push rdx + + call NumberToString ; RSI=string, ECX=len + mov eax, ecx ; EAX = len + + cmp eax, 2 + jl .no1 + + test eax, 1 + jnz .no1 ; odd length => cannot be AA + + shr eax, 1 ; half = len/2 + mov r8d, eax ; half + xor r9d, r9d ; i = 0 + +.loop1: + cmp r9d, r8d + jge .yes1 + + ; s[i] + mov rdx, r9 + movzx eax, byte [rsi + rdx] + + ; s[i+half] + mov rdx, r9 + add rdx, r8 + movzx ebx, byte [rsi + rdx] + + cmp eax, ebx + jne .no1 + + inc r9d + jmp .loop1 + +.yes1: + mov rax, 1 + jmp .ret1 + +.no1: + xor rax, rax + +.ret1: + pop rdx + pop rbx + ret + +; CheckInvalid2: any repeating block >= 2 +; RAX = number +; Returns RAX = 1 if string is some A repeated k>=2 times +CheckInvalid2: + push rbx + push rdx + + call NumberToString ; RSI=string, ECX=len + mov r11d, ecx ; n = length + + cmp r11d, 2 + jb .no2 + + mov r8d, 1 ; m = 1 (candidate period) +.outer: + cmp r8d, r11d + jge .no2 + + ; if n % m != 0 => cannot tile + mov eax, r11d + xor edx, edx + div r8d ; EAX=q, EDX=r + test edx, edx + jnz .next_m + + mov r9d, r11d + sub r9d, r8d ; limit = n - m + xor r10d, r10d ; i = 0 +.inner: + cmp r10d, r9d + jge .yes2 ; all positions checked + + ; s[i] + mov rdx, r10 + movzx eax, byte [rsi + rdx] + + ; s[i+m] + mov rdx, r10 + add rdx, r8 + movzx ebx, byte [rsi + rdx] + + cmp eax, ebx + jne .next_m + + inc r10d + jmp .inner +.yes2: + mov rax, 1 + jmp .ret2 +.next_m: + inc r8d + jmp .outer +.no2: + xor rax, rax +.ret2: + pop rdx + pop rbx + ret + +Newline: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, newline + mov rdx, 1 + syscall + ret + +PrintInt64: + mov rdi, numberBuffer+31 + mov byte [rdi], 0 + dec rdi + + cmp rax, 0 + jne .conv + + mov byte [rdi], '0' + jmp .done +.conv: + mov rbx, 10 +.next: + xor rdx, rdx + div rbx + add dl, '0' + mov [rdi], dl + dec rdi + test rax, rax + jnz .next + + inc rdi +.done: + mov rax, SYS_WRITE + mov rsi, rdi + mov rdi, STDOUT + mov rdx, numberBuffer+31 + sub rdx, rsi + syscall + ret + +PrintString: + push rcx + push rdx + mov rdx, 0 +.length: + cmp byte [rcx+rdx], 0 + je .submit + inc rdx + jmp .length +.submit: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, rcx + syscall + pop rdx + pop rcx + ret diff --git a/aoc-2025/day3.asm b/aoc-2025/day3.asm new file mode 100644 index 0000000..e547475 --- /dev/null +++ b/aoc-2025/day3.asm @@ -0,0 +1,301 @@ +; Advent of Code 2025 - Day 3 + +bits 64 +default rel + +global _start + +%define SYS_EXIT 60 +%define SYS_READ 0 +%define SYS_WRITE 1 +%define SYS_OPEN 2 +%define SYS_CLOSE 3 + +%define O_RDONLY 0 +%define STDOUT 1 + +section .data + inputPath db "input/day3.txt", 0 + + newline db 10 + + label1 db "Part 1: ", 0 + label2 db "Part 2: ", 0 + +section .bss + buffer resb 4096 + lineBuffer resb 65536 + lineLen resd 1 + + sum1 resq 1 + sum2 resq 1 + + workDigits resb 64 ; stack for greedy subsequence + numberBuffer resb 32 ; for printing + +section .text + +_start: + mov rax, SYS_OPEN + mov rdi, inputPath + mov rsi, O_RDONLY + xor rdx, rdx + syscall + + mov r12, rax ; fd + mov dword [lineLen], 0 + +ReadLoop: + mov rax, SYS_READ + mov rdi, r12 + mov rsi, buffer + mov rdx, 4096 + syscall + + cmp rax, 0 + jle EOF + + mov rdi, buffer + mov rbp, rax + +ScanChunk: + cmp rbp, 0 + je ReadLoop + + mov al, [rdi] + + cmp al, 13 + je SkipCR + + cmp al, 10 + je EndLine + + mov edx, [lineLen] + cmp edx, 65535 + jae SkipStore + mov [lineBuffer+rdx], al + inc edx + mov [lineLen], edx + +SkipStore: + inc rdi + dec rbp + jmp ScanChunk + +SkipCR: + inc rdi + dec rbp + jmp ScanChunk + +EndLine: + mov edx, [lineLen] + mov byte [lineBuffer+edx], 0 + + cmp edx, 0 + je ClearLine + + push rdi + mov rsi, lineBuffer + call HandleLine + pop rdi + +ClearLine: + mov dword [lineLen], 0 + inc rdi + dec rbp + jmp ScanChunk + +EOF: + ; possible last partial line + mov edx, [lineLen] + cmp edx, 0 + jle PrintResults + + mov byte [lineBuffer+edx], 0 + mov rsi, lineBuffer + call HandleLine + +PrintResults: + mov rcx, label1 + call PrintString + mov rax, [sum1] + call PrintInt64 + call Newline + + mov rcx, label2 + call PrintString + mov rax, [sum2] + call PrintInt64 + call Newline + + mov rax, SYS_CLOSE + mov rdi, r12 + syscall + + mov rax, SYS_EXIT + xor rdi, rdi + syscall + +HandleLine: + mov rdi, rsi + xor ecx, ecx ; ECX = 0 +.lengthLoop: + mov al, [rdi+rcx] + cmp al, 0 + je .lengthDone + inc ecx + jmp .lengthLoop +.lengthDone: + mov r15d, ecx ; r15d = n + + ; part 1: k = 2 + mov ecx, r15d ; ECX = n + mov edi, 2 ; K = 2 + call GetMaxForK ; RAX = best 2-digit value + add qword [sum1], rax + + ; part 2: k = 12, only if n >= 12 + cmp r15d, 12 + jl .skipPart2 + + mov ecx, r15d + mov edi, 12 + call GetMaxForK ; RAX = best 12-digit value + add qword [sum2], rax + +.skipPart2: + ret + +; Greedy lexicographically largest subsequence of length K +; +; Input: +; RSI -> digits string +; ECX = n (length) +; EDI = k +; Output: +; RAX = numeric value of chosen k digits +; Clobbers: R8..R11, EAX, EDX +GetMaxForK: + ; dropsRemaining = n - k + mov eax, ecx + sub eax, edi + mov r8d, eax ; r8d = drops + + xor r9d, r9d ; r9d = stackSize + xor r10d, r10d ; r10d = i + +.loop: + cmp r10d, ecx + jge .after_input + + ; current digit in AL + mov r11, r10 + mov al, [rsi + r11] + +.pop: + cmp r9d, 0 + jle .push + cmp r8d, 0 + jle .push + + mov edx, r9d + dec edx + mov r11d, edx + mov bl, [workDigits + r11] + + cmp bl, al + jge .push + + dec r9d + dec r8d + jmp .pop +.push: + mov r11d, r9d + mov [workDigits + r11], al + inc r9d + inc r10d + jmp .loop + +.after_input: + ; trim if stackSize > k +.trim: + cmp r9d, edi + jle .convert + dec r9d + jmp .trim +.convert: + xor rax, rax + xor r11d, r11d +.convertLoop: + cmp r11d, edi + jge .done + + mov rdx, r11 + mov dl, [workDigits + rdx] + sub dl, '0' + movzx rdx, dl + + imul rax, rax, 10 + add rax, rdx + + inc r11d + jmp .convertLoop +.done: + ret + +Newline: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, newline + mov rdx, 1 + syscall + ret + +PrintInt64: + mov rdi, numberBuffer+31 + mov byte [rdi], 0 + dec rdi + + cmp rax, 0 + jne .conv + + mov byte [rdi], '0' + jmp .done +.conv: + mov rbx, 10 +.next: + xor rdx, rdx + div rbx + add dl, '0' + mov [rdi], dl + dec rdi + test rax, rax + jnz .next + + inc rdi +.done: + mov rax, SYS_WRITE + mov rsi, rdi + mov rdi, STDOUT + mov rdx, numberBuffer+31 + sub rdx, rsi + syscall + ret + +PrintString: + push rcx + push rdx + mov rdx, 0 +.length: + cmp byte [rcx+rdx], 0 + je .submit + inc rdx + jmp .length +.submit: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, rcx + syscall + pop rdx + pop rcx + ret diff --git a/aoc-2025/day4.asm b/aoc-2025/day4.asm new file mode 100644 index 0000000..475f2ef --- /dev/null +++ b/aoc-2025/day4.asm @@ -0,0 +1,25 @@ +bits 64 +default rel + +global _start + +%define SYS_EXIT 60 +%define SYS_WRITE 1 + +%define STDOUT 1 + +section .data + message db "Hello Day 4!", 0xA + length equ $-message + +section .text +_start: + mov rax, SYS_WRITE + mov rdi, STDOUT + mov rsi, message + mov rdx, length + syscall + + mov rax, SYS_EXIT + xor rdi, rdi + syscall -- cgit v1.3