feat(day1): complete day 1 task

Author: NishantJoshi00

README.md

@@ -6,7 +6,7 @@ This is a repository contiaining the solution for advent of code problems of 202
 
 Here is the list of the problems solved and language used to solve them
 
-- [ ] Day 1 - Assembly
+- [x] Day 1 - Assembly
 - [ ] Day 2
 - [ ] Day 3
 - [ ] Day 4

day-1/.gitignore

@@ -1,2 +1,4 @@
+*.in
 *.o
-*.out
+solution
+solution2

day-1/Makefile

@@ -0,0 +1,24 @@
+
+
+solution.o: solution.asm
+	nasm -f elf64 solution.asm -o solution.o
+
+solution: solution.o
+	ld solution.o -o solution
+
+build: solution
+
+build2: solution2
+
+solution2: solution2.o
+	ld solution2.o -o solution2
+
+solution2.o: solution2.asm
+	nasm -f elf64 solution2.asm -o solution2.o
+
+run: build
+	./solution
+
+clean:
+	rm solution.o
+	rm solution

day-1/solution.asm

@@ -0,0 +1,153 @@
+SYS_WRITE   equ 1 ; write text to stdout
+SYS_READ    equ 0 ; read text from stdin
+SYS_EXIT    equ 60 ; terminate the program
+STDOUT      equ 1 ; stdout
+STDIN       equ 0 ; stdin
+LENGTH      equ 1 ; Length to read
+NEWLINE     equ 10; ASCII newline
+
+;--------------------------------------------------------------------------
+
+section .bss
+    current resb 1 ; To store the current 
+    first   resb 1 ; To store the first digit
+    second  resb 1 ; To store the second digit
+    first_done  resb 1 ; To store the second digit
+    total   resq 1 ; To store the total
+    buffer  resb 22
+
+
+;--------------------------------------------------------------------------
+
+section .text
+    global _start
+
+
+input:
+    mov     rax, SYS_READ
+    mov     rdi, STDIN
+    mov     rdx, LENGTH
+    mov     rsi, current
+    syscall
+
+
+    cmp rax, 0
+    je reset_exit
+
+    ret
+
+exit:
+    xor     edi, edi  
+    mov     rax, SYS_EXIT
+    syscall
+
+output:
+    mov     rax, rdi           
+    mov     rdi, buffer + 20   
+    mov     rcx, 10            
+    mov     rbx, 0             
+
+.repeat:
+    dec     rdi                
+    xor     rdx, rdx          
+    div     rcx              
+    add     dl, '0'         
+    mov     [rdi], dl      
+    inc     rbx                
+
+    test    rax, rax           
+    jnz     .repeat            
+
+    ; rbx now contains the number of digits in the string
+
+    ; Move the string to the beginning of the buffer
+
+    mov     rsi, rdi
+    add     rsi, 20
+    mov     byte [rsi], NEWLINE
+    add     rsi, 1
+    mov     byte [rsi], 0
+    mov     rsi, rdi
+    mov     rdi, STDOUT          ; Use STDOUT as file descriptor
+    sub     rdx, rbx             ; Calculate string length
+    mov     rax, SYS_WRITE       ; syscall number for sys_write
+    syscall
+
+    ret
+
+main:
+  call input
+
+  movzx rax, byte [current]
+
+  cmp rax, NEWLINE
+  je reset
+
+
+  cmp rax, '0'
+  jl main
+  cmp rax, '9'
+  jg main
+
+  sub byte [current], '0'
+  
+  cmp byte [first_done], 0
+  je do_first
+
+  jmp do_second
+
+
+  call exit
+  
+do_first:
+  mov al, byte [current]
+  mov byte [first], al
+  mov byte [second], al
+  mov byte [first_done], 1
+  jmp main
+
+do_second:
+  mov al, byte [current]
+  mov byte [second], al
+  jmp main
+
+do_stuff:
+  movzx rax, byte [first]
+  imul rax, 10
+  add qword [total], rax
+  movzx rax, byte [second]
+  add qword [total], rax
+  ret
+
+reset:
+  call do_stuff
+
+  mov     byte [first], 0
+  mov     byte [second], 0
+  mov     byte [first_done], 0
+
+  mov     rdi, qword [total]
+  call    output
+
+  jmp main
+
+reset_exit:
+  call do_stuff
+
+  mov     rdi, qword [total]
+  call    output
+
+  call exit
+
+  
+
+_start:
+    mov     qword [total], 0
+    mov     byte [first], 0
+    mov     byte [second], 0
+    mov     byte [first_done], 0
+
+    call main
+
+
+