Move all Advent of Codes into one repo

1 files changed, 30 insertions, 0 deletions

diff --git a/2020/10/possible_seq.asm b/2020/10/possible_seq.asm
new file mode 100644
index 0000000..b737d13
--- /dev/null
+++ b/2020/10/possible_seq.asm
@@ -0,0 +1,30 @@
+global possible_seq
+
+section .rodata
+    TRIB:   dq 1, 1, 2, 4, 7                ; tribonacci sequence (without first 2 zeroes)
+
+section .text
+
+possible_seq:
+    mov         eax, 1                      ; set up return value
+    xor         ecx, ecx                    ; # of connected elements counter
+    lea         rdx, [rdi + 4 * rsi - 4]    ; pointer to the last element
+    lea         r8, [rel TRIB]
+    jmp         .loop
+.ncon:
+    imul        rax, qword [r8 + 8 * rcx]
+    xor         ecx, ecx
+    add         rdi, 4
+    cmp         rdi, rdx
+    jae         .return
+.loop:
+    mov         esi, dword [rdi + 4]
+    sub         esi, dword [rdi]
+    cmp         esi, 1
+    jne         .ncon
+    inc         ecx
+    add         rdi, 4
+    cmp         rdi, rdx
+    jb          .loop
+.return:
+    ret