diff --git "a/AlgorithmReview/Programmers/Lv3/\355\214\214\352\264\264\353\220\230\354\247\200 \354\225\212\354\235\200 \352\261\264\353\254\274.swift" "b/AlgorithmReview/Programmers/Lv3/\355\214\214\352\264\264\353\220\230\354\247\200 \354\225\212\354\235\200 \352\261\264\353\254\274.swift"
index 48bd3e7..b4d4580 100644
--- "a/AlgorithmReview/Programmers/Lv3/\355\214\214\352\264\264\353\220\230\354\247\200 \354\225\212\354\235\200 \352\261\264\353\254\274.swift"	
+++ "b/AlgorithmReview/Programmers/Lv3/\355\214\214\352\264\264\353\220\230\354\247\200 \354\225\212\354\235\200 \352\261\264\353\254\274.swift"	
@@ -7,7 +7,7 @@
 
 import Foundation
 
-func solution(_ board:[[Int]], _ skill:[[Int]]) -> Int {
+func timeout(_ board:[[Int]], _ skill:[[Int]]) -> Int {
     
     let (row, col) = (board.count, board[0].count)
     
@@ -31,3 +31,44 @@ func solution(_ board:[[Int]], _ skill:[[Int]]) -> Int {
     }
     return ans
 }
+
+func reference(_ board:[[Int]], _ skill:[[Int]]) -> Int {
+    
+    let (row, col) = (board.count, board[0].count)
+    var temp = [[Int]](repeating: [Int](repeating: 0, count: col+1), count: row+1)
+    
+    for s in skill {
+        let (type, r1, c1, r2, c2) = (s[0], s[1], s[2], s[3], s[4])
+        let degree = type == 2 ? s[5] : -s[5]
+        temp[r1][c1] += degree
+        temp[r1][c2+1] += -degree
+        temp[r2+1][c1] += -degree
+        temp[r2+1][c2+1] += degree
+    }
+ 
+    // 행 기준 누적합
+    for i in 0..<row{
+        for j in 0..<col{
+            temp[i][j+1] += temp[i][j]
+        }
+    }
+ 
+    // 열 기준 누적합
+    for i in 0..<row{
+        for j in 0..<col{
+            temp[i+1][j] += temp[i][j]
+        }
+    }
+ 
+    var board = board
+    var ans = 0
+    for i in 0..<row{
+        for j in 0..<col{
+            board[i][j] += temp[i][j]
+            if board[i][j] > 0{
+                ans += 1
+            }
+        }
+    }
+    return ans
+}