%include "io.inc"

; <memory_reserved>
%macro cdecl_prologue 1
    push ebp
    mov ebp, esp
    sub esp, %1
%endmacro

%macro cdecl_epilogue 0
    leave
    ret
%endmacro

section .bss
parr: resd 1
fin: resd 1
fout: resd 1

section .rodata
fin_name: db "C:/input.bin", 0
fout_name: db "C:/output.bin", 0
fin_fmt: db "rb", 0
fout_fmt: db "wb", 0

N equ 2000000

section .text
CEXTERN malloc
CEXTERN free
CEXTERN fopen
CEXTERN fclose
CEXTERN fread
CEXTERN fwrite

global CMAIN
CMAIN:
    sub esp, 32

    mov dword[esp + 4], N * 4
    call malloc
    mov dword[parr], eax

    mov dword[esp + 8], fin_fmt
    mov dword[esp + 4], fin_name
    call fopen
    mov dword[fin], eax

    mov dword[esp + 8], fout_fmt
    mov dword[esp + 4], fout_name
    call fopen
    mov dword[fout], eax

;    mov eax, dword[fin]
;    mov dword[esp + 16], eax
;    mov dword[esp + 12], N
;    mov dword[esp + 8], 4
;    mov eax, dword[parr]
;    mov dword[esp + 4], eax
;    call fread
;
;    mov dword[esp + 8], eax
;    mov eax, dword[parr]
;    mov dword[esp + 4], eax
;    call is_pyramid
;
;    mov dword[esp + 20], eax
;    mov eax, dword[fout]
;    mov dword[esp + 16], eax
;    mov dword[esp + 12], 1
;    mov dword[esp + 8], 4
;    lea eax, [esp + 20]
;    mov dword[esp + 4], eax
;    call fwrite

    mov eax, dword[fin]
    mov dword[esp + 4], eax
    call fclose

    mov eax, dword[fout]
    mov dword[esp + 4], eax
    call fclose

    mov eax, dword[parr]
    mov dword[esp + 4], eax
    call free

    add esp, 32
    xor eax, eax
    ret

; ebp + 12  : int n
; ebp + 8   : int *arr
is_pyramid_element:
    cdecl_prologue 8
    mov dword[esp + 8], 0; last
    mov dword[esp + 4], 1; result

    .loop1:
        cmp dword[ebp + 12], 0
        jz .end_loop1
        mov eax, dword[ebp + 12]
        mov dword[esp + 8], eax

        ; n = (n + 1) / 2 - 1
        inc eax
        xor edx, edx
        mov ecx, 2
        div ecx
        sub eax, 1
        mov dword[ebp + 12], eax

        ; if ((arr[last] - arr[n]) * result < 0)
        mov ecx, dword[ebp + 8]
        mov eax, dword[ecx + 4 * eax]

        mov edx, dword[esp + 8]
        sub eax, dword[ecx + 4 * edx]

        mul dword[esp + 4]
        cmp eax, 0
        jle .loop1

        cmp dword[esp + 4], 1
        jne .l1

        mov dword[esp + 4], -1
        jmp .loop1

        .l1:

        mov eax, 0
        cdecl_epilogue

        jmp .loop1
    .end_loop1:

    mov eax, dword[esp + 4]
    cdecl_epilogue

; ebp + 12  : int size
; ebp + 8   : int *arr
is_pyramid:
    cdecl_prologue 24
    ; [esp + 4; esp + 8] : f_args
    mov dword[esp + 12], 1; result

    mov eax, dword[ebp + 12]
    mov ecx, 2
    div ecx
    mov ecx, eax

    .loop1:
        cmp ecx, dword[ebp + 12]
        jae .end_loop1

        ;mov eax, dword[ebp + 12]
        mov dword[esp + 8], ecx
        mov eax, dword[ebp + 8]
        mov dword[esp + 4], eax

        mov dword[esp + 16], ecx; save
        call is_pyramid_element
        mov ecx, dword[esp + 16]; load

        test eax, eax
        jnz .l1

        cdecl_epilogue

        .l1:

        mul dword[esp + 12]
        cmp eax, 0
        jge .next1

        cmp dword[esp + 12], 1
        jne .l2

        mov dword[esp + 12], -1
        jmp .next1

        .l2:

        mov eax, 0
        cdecl_epilogue

        .next1:
        inc ecx
        jmp .loop1
    .end_loop1:

    mov eax, dword[esp + 12]
    cdecl_epilogue