4 files changed, 55 insertions, 0 deletions
diff --git a/06-Sum-Square-Difference/asm/Makefile b/06-Sum-Square-Difference/asm/Makefile
new file mode 100644
index 0000000..68e7f4f
--- /dev/null
+++ b/06-Sum-Square-Difference/asm/Makefile
@@ -0,0 +1,6 @@
+sumsq: sumsq.o
+	gcc sumsq.o -o sumsq 
+sumsq.o: sumsq.asm
+	nasm -w+all -f elf64 -g -F stabs sumsq.asm
+clean:
+	rm -f sumsq sumsq.o
diff --git a/06-Sum-Square-Difference/asm/sumsq b/06-Sum-Square-Difference/asm/sumsq
new file mode 100755
index 0000000..d282ab2
--- /dev/null
+++ b/06-Sum-Square-Difference/asm/sumsq
diff --git a/06-Sum-Square-Difference/asm/sumsq.asm b/06-Sum-Square-Difference/asm/sumsq.asm
new file mode 100644
index 0000000..cc9295a
--- /dev/null
+++ b/06-Sum-Square-Difference/asm/sumsq.asm
@@ -0,0 +1,49 @@
+; Find the difference between (1+2+3+...+100)^2 and (1^2+2^2+3^2+...+100^2)
+; I used another math trick here:
+; The sum up to a number can be found using Gauss' Trick:
+; 1 + 2 + 3 + ... + 10 -> (1+9) + (2+8) + (3+7) + (4+6) + 10 + 5 -> 5*10 +5
+; In general : (n/2)(n+1)
+
+extern printf
+SECTION .data
+flag:   db  "%d",10,0           ; "%d\n\0"
+
+SECTION .text
+    global main    
+    global is_divisible
+
+main:
+        push rbp                ; set up stack
+        mov rbp, rsp
+
+        ; first square of sum (1+2+...100)^2
+        mov rax, 50             ; sum = n/2 
+        mov rcx, 101            ; * (n + 1)
+        mul rcx
+        mul rax                 ; square it
+        push rax                ; save it
+        
+        ; now sum the squares (1^2+2^2 ...) no short cut this time
+        xor r11, r11            ; This will store the sum, rcx will b n, 
+                                ; rax is just used to multiply
+        mov rcx, 0              ; n = 0, we add one first
+
+.loop   inc rcx                 ; see? told you :)
+        mov rax, rcx            ; move into multiply register
+        mul rax                 ; multiply by itself
+        add r11, rax            ; add to the sum
+        cmp rcx, 100            
+        jne .loop
+
+        pop rax                 ; sum of the squares is on the stack
+        sub rax, r11            ; take the difference, rax - r11
+                                ; square of the sum is bigger
+.print  mov rdi, flag           ; arg 1 (format)
+        mov rsi, rax            ; arg 2 (value)
+        mov rax, 0		; no xmm registers
+        call printf wrt ..plt
+        pop rbp
+
+        mov rax, 0
+        ret
+
diff --git a/06-Sum-Square-Difference/asm/sumsq.o b/06-Sum-Square-Difference/asm/sumsq.o
new file mode 100644
index 0000000..9b0a44b
--- /dev/null
+++ b/06-Sum-Square-Difference/asm/sumsq.o