Merge pull request #174 from HmmCorn/liv

가장 긴 팰린드롬

Author: sangYuLv

WEEK16/프로그래머스_가장긴팰린드롬/liv.swift

@@ -0,0 +1,38 @@
+// 프로그래머스 - 가장 긴 팰린드롬
+
+import Foundation
+
+func solution(_ s: String) -> Int {
+    let chars = Array(s)
+    let n = chars.count
+
+    var dp = Array(repeating: Array(repeating: false, count: n), count: n)
+
+    var answer = 1
+
+    for i in 0..<n {
+        dp[i][i] = true
+    }
+
+    if n >= 2 {
+        for i in 0..<(n - 1) where chars[i] == chars[i + 1] {
+            dp[i][i + 1] = true
+            answer = 2
+        }
+    }
+
+    if n >= 3 {
+        for length in 3...n {
+            for start in 0...(n - length) {
+                let end = start + length - 1
+
+                if chars[start] == chars[end] && dp[start + 1][end - 1] {
+                    dp[start][end] = true
+                    answer = length
+                }
+            }
+        }
+    }
+
+    return answer
+}