diff --git a/1/homework/exp2/a.in b/1/homework/exp2/a.in
new file mode 100644
index 0000000..2fdfd43
Binary files /dev/null and b/1/homework/exp2/a.in differ
diff --git a/1/homework/exp2/insert_sort.asm b/1/homework/exp2/insert_sort.asm
new file mode 100644
index 0000000..f879fdb
--- /dev/null
+++ b/1/homework/exp2/insert_sort.asm
@@ -0,0 +1,188 @@
+.data   
+compare_count:      .word   0
+num_N:              .word   0
+input_file_name:    .asciiz "a.in"
+                    .align  2
+output_file_name:   .asciiz "a.out"
+                    .align  2
+space_string:       .asciiz " "
+                    .align  2
+newline_string:     .asciiz "\r\n"
+                    .align  2
+num_buff:           .space  4096
+                    .align  2
+
+.text   
+main:               
+    la      $a0,                input_file_name
+    li      $a1,                0
+    li      $a2,                0
+    li      $v0,                13
+    syscall 
+
+    move    $a0,                $v0                                     # start to read in N
+    la      $a1,                num_N
+    li      $a2,                4
+    li      $v0,                14
+    syscall 
+
+    la      $t0,                num_N                                   # read N * 4 bytes into num_buff
+    lw      $a2,                0($t0)                                  # read in num_N
+    sll     $a2,                $a2,                2                   # n * 4 is the bytes to read
+
+    la      $a1,                num_buff
+
+    li      $v0,                14
+    syscall                                                             # read in file
+    li      $v0,                16
+    syscall                                                             # close file
+
+    jal     insertion_sort
+
+    la      $a0,                output_file_name
+    li      $a1,                1
+    li      $a2,                0
+    li      $v0,                13
+    syscall 
+
+    move    $a0,                $v0
+    la      $a1,                compare_count
+    li      $a2,                4
+    li      $v0,                15
+    syscall 
+
+    la      $a1,                num_buff
+    la      $a2,                num_N
+    lw      $a2,                0($a2)
+    sll     $a2,                $a2,                2
+    li      $v0,                15
+    syscall 
+
+    li      $v0,                17
+    syscall                                                             # exit
+
+insertion_sort:     
+    subi    $sp,                $sp,                4
+    sw      $ra,                0($sp)
+
+    la      $t0,                num_N
+    lw      $s0,                0($t0)                                  # n in s0
+
+    li      $s1,                1                                       # i in s1
+item_loop:          
+    bge     $s1,                $s0,                done_item_loop      # if i >= n, done loop
+    move    $a0,                $s1
+    jal     search
+
+    move    $a0,                $v0
+    move    $a1,                $s1
+    jal     insert
+
+    addi    $s1,                $s1,                1                   # i ++
+    j       item_loop
+done_item_loop:     
+
+    lw      $ra,                0($sp)
+    addi    $sp,                $sp,                8
+    jr      $ra
+
+search:                                                                 # $a0: int n
+    subi    $sp,                $sp,                12
+    sw      $s0,                8($sp)
+    sw      $s1,                4($sp)
+    sw      $ra,                0($sp)
+
+    la      $s0,                num_buff
+    sll     $t0,                $a0,                2
+    add     $s2,                $s0,                $t0
+    lw      $s2,                0($s2)                                  # s2 = tmp = v[n]
+
+    subi    $s1,                $a0,                1                   # i = n - 1
+search_loop:        
+    bltz    $s1,                done_search_loop                        # i < 0, done loop
+    jal     add_compare_count
+
+    sll     $t0,                $s1,                2
+    add     $t0,                $s0,                $t0
+    lw      $t0,                0($t0)                                  # t0 = v[i]
+    ble     $t0,                $s2,                done_search_loop    # if v[i] <= tmp, break
+
+    subi    $s1,                $s1,                1                   # i--
+    j search_loop
+
+done_search_loop:   
+    addi    $v0,                $s1,                1                   # return i + 1
+
+    lw      $s0,                8($sp)
+    lw      $s1,                4($sp)
+    lw      $ra,                0($sp)
+    addi    $sp,                $sp,                12
+    jr      $ra
+insert:                                                                 # $a0: int k, $a1: int n
+    subi    $sp,                $sp,                12
+    sw      $s0,                8($sp)
+    sw      $s1,                4($sp)
+    sw      $ra,                0($sp)
+
+    la      $s0,                num_buff                                # s0 = &v[0]
+
+    sll     $t0,                $a1,                2
+    add     $s2,                $s0,                $t0
+    lw      $s2,                0($s2)                                  # s2 = tmp = 'pivot' = v[n]
+
+    subi    $s1,                $a1,                1                   # s1 = i = n - 1
+
+insert_loop:        
+    blt     $s1,                $a0,                done_insert_loop    # i < k, done loop
+    sll     $t0,                $s1,                2
+    add     $t0,                $s0,                $t0                 # t0 = &v[i]
+    lw      $t1,                0($t0)
+    sw      $t1,                4($t0)
+
+    subi    $s1,                $s1,                1                   # i--
+    j       insert_loop
+done_insert_loop:   
+    sll     $t0,                $a0,                2
+    add     $t0,                $s0,                $t0
+    sw      $s2,                0($t0)                                  # t0 = &v[k]
+
+    lw      $s0,                8($sp)
+    lw      $s1,                4($sp)
+    lw      $ra,                0($sp)
+    addi    $sp,                $sp,                12
+    jr      $ra
+
+
+add_compare_count:  
+    la      $t0,                compare_count
+    lw      $t1,                0($t0)
+    addi    $t1,                $t1,                1
+    sw      $t1,                0($t0)
+    jr      $ra
+
+print_num_in_buff:  
+    la      $t0,                num_N
+    la      $t2,                num_buff
+    lw      $t0,                0($t0)
+    li      $t1,                0
+print_loop:         
+    bge     $t1,                $t0,                done_print_loop
+
+    sll     $a0,                $t1,                2
+    add     $a0,                $t2,                $a0
+    lw      $a0,                0($a0)
+    li      $v0,                1
+    syscall 
+
+    la      $a0,                space_string
+    li      $v0,                4
+    syscall 
+
+    addi    $t1,                $t1,                1
+    j       print_loop
+
+done_print_loop:    
+    la      $a0,                newline_string
+    li      $v0,                4
+    syscall 
+    jr      $ra