Merge pull request #2525 from sangbeenmoon/main

[sangbeenmoon] WEEK 06 Solutions

Author: sangbeenmoon

design-add-and-search-words-data-structure/sangbeenmoon.java

@@ -0,0 +1,63 @@
+import java.util.HashMap;
+import java.util.Map;
+
+class WordDictionary {
+
+
+    Map<Character, WordDictionary> map;
+    boolean isEnd = false;
+
+    public WordDictionary() {
+        map = new HashMap<>();
+    }
+    
+    public void addWord(String word) {
+        char ch = word.charAt(0);
+        WordDictionary node;
+        if (map.containsKey(ch)) {
+            node = map.get(ch);
+        } else {
+            node = new WordDictionary();
+        }
+
+        map.put(ch, node);
+
+        if (word.length() == 1) {
+            node.isEnd = true;
+            return;    
+        }
+
+        node.addWord(word.substring(1));
+    }
+    
+    public boolean search(String word) {
+        if (word.length() == 0) {
+            return isEnd;
+        }
+
+        char ch = word.charAt(0);
+        WordDictionary node;
+
+        if (ch == '.') {
+            for (Map.Entry<Character, WordDictionary> entry : map.entrySet()) {
+                if (entry.getValue().search(word.substring(1))){
+                    return true;
+                }
+            }
+        }
+
+        if (map.containsKey(ch)) {
+            node = map.get(ch);
+            return node.search(word.substring(1));
+        }
+
+        return false;
+    }
+}
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * WordDictionary obj = new WordDictionary();
+ * obj.addWord(word);
+ * boolean param_2 = obj.search(word);
+ */

longest-increasing-subsequence/sangbeenmoon.py

@@ -0,0 +1,27 @@
+# hint 를 보고 해결.
+# DP 로도 풀 수 있음.
+
+class Solution:
+    def lengthOfLIS(self, nums: List[int]) -> int:
+        seq = []
+
+
+        for num in nums:
+            if len(seq) == 0:
+                seq.append(num)
+                continue
+
+            i = 0
+            
+            while seq[i] < num:
+                i = i + 1
+
+                if i > len(seq) - 1:
+                    break
+            
+            if i > len(seq) - 1:
+                seq.append(num)
+            else:
+                seq[i] = num
+    
+        return len(seq)

spiral-matrix/sangbeenmoon.py

@@ -0,0 +1,40 @@
+# 우 -> 하 -> 좌 -> 상
+
+class Solution:
+    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+        dx = [1, 0, -1, 0]
+        dy = [0, 1, 0, -1]
+
+        rows, cols = len(matrix), len(matrix[0])
+
+        visited = [[False] * cols for _ in range(rows)]
+
+        answer = []
+
+        def dfs(xx: int, yy:int, d:int):
+
+            i = d
+            cnt = 0
+            while cnt <= 5:
+                nx = xx + dx[i]
+                ny = yy + dy[i]
+
+                if 0 <= nx and nx < cols and 0 <= ny and ny < rows:
+                    if not visited[ny][nx]:
+                        visited[ny][nx] = True
+                        answer.append(matrix[ny][nx])
+                        dfs(nx,ny,i)
+                        return
+                if i == 3:
+                    i = 0
+                else:
+                    i = i + 1
+                cnt = cnt + 1
+                
+                        
+        
+        visited[0][0] = True
+        answer.append(matrix[0][0])
+        dfs(0,0,0)
+                        
+        return answer