[Blossssom] WEEK 06 solutions

container-with-most-water/Blossssom.ts

@@ -0,0 +1,34 @@
+/**
+ * @param height - 정수 배열
+ * @returns - 용기에 담을 수 있는 최대 물의 양
+ * @description
+ * - 양 끝에서 2포인터를 사용해 크기를 체크해 나아감
+ * - 결국 거리가 짧아지기 때문에 양쪽 높이를 비교하며 높이가 낮은 포인터를 움직이며 계산
+ * - 시간 복잡도 O(n)
+ */
+
+function maxArea(height: number[]): number {
+  let left = 0;
+  let right = height.length - 1;
+  let water = 0;
+
+  while (left < right) {
+    const calcWater = (right - left) * Math.min(height[left], height[right]);
+    if (water < calcWater) {
+      water = calcWater;
+    }
+
+    if (height[left] < height[right]) {
+      left++;
+    } else {
+      right--;
+    }
+  }
+
+  return water;
+}
+
+const height = [1, 3, 2, 5, 25, 24, 5];
+const result = maxArea(height);
+
+

design-add-and-search-words-data-structure/Blossssom.ts

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+/**
+ * @class - Dictionary 구현
+ * @description
+ * - .의 경우 모든 문자와 일치
+ * - .일 경우 결국 모든 children 조회필요 => dfs
+ */
+
+class WordNode {
+  children: { [key: string]: WordNode };
+  endOfWord: boolean;
+  constructor() {
+    this.children = {};
+    this.endOfWord = false;
+  }
+}
+
+class WordDictionary {
+  private rootNode: WordNode;
+  constructor() {
+    this.rootNode = new WordNode();
+  }
+
+  addWord(word: string): void {
+    let nodeInstance = this.rootNode;
+
+    for (const str of word) {
+      if (!nodeInstance.children[str]) {
+        nodeInstance.children[str] = new WordNode();
+      }
+      nodeInstance = nodeInstance.children[str];
+    }
+
+    nodeInstance.endOfWord = true;
+  }
+
+  search(word: string): boolean {
+    return this.searchDfs(this.rootNode, word, 0);
+  }
+
+  private searchDfs(currentNode: WordNode, word: string, idx: number): boolean {
+    if (idx === word.length) {
+      return currentNode.endOfWord;
+    }
+
+    const char = word[idx];
+    if (char === ".") {
+      for (const key in currentNode.children) {
+        const childSearch = this.searchDfs(
+          currentNode.children[key],
+          word,
+          idx + 1
+        );
+        if (childSearch) {
+          return true;
+        }
+      }
+
+      return false;
+    } else {
+      if (!currentNode.children[char]) {
+        return false;
+      }
+
+      return this.searchDfs(currentNode.children[char], word, idx + 1);
+    }
+  }
+}
+
+const wordDict = new WordDictionary();
+
+wordDict.addWord("at");
+wordDict.addWord("and");
+wordDict.addWord("an");
+wordDict.addWord("add");
+
+wordDict.search("a"); // false
+wordDict.search(".at"); // false
+
+wordDict.addWord("bat");
+
+wordDict.search(".at"); // true
+wordDict.search("an."); // true
+wordDict.search("a.d."); // false
+wordDict.search("b."); // false
+wordDict.search("a.d"); // true
+wordDict.search("."); // false
+
+
+

longest-increasing-subsequence/Blossssom.ts

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+/**
+ * @param nums - 정수 배열
+ * @returns - 엄격하게 증가하는 요소의 길이 반환
+ */
+function lengthOfLIS(nums: number[]): number {
+  const arr: number[] = Array.from({ length: nums.length }, () => 1);
+  let maxLen = 1;
+  for (let i = 1; i < nums.length; i++) {
+    for (let j = 0; j < i; j++) {
+      if (nums[i] > nums[j]) {
+        arr[i] = Math.max(arr[i], arr[j] + 1);
+      }
+    }
+    maxLen = Math.max(maxLen, arr[i]);
+  }
+
+  return maxLen;
+}
+
+const nums = [0, 1, 0, 3, 2, 3];
+lengthOfLIS(nums);
+
+

valid-parentheses/Blossssom.ts

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+/**
+ * @param s - 괄호 문자열
+ * @returns - 올바르게 열고 닫혔는지 반환
+ */
+// function isValid(s: string): boolean {
+//   const parentheses: Record<string, boolean> = {
+//     "()": true,
+//     "{}": true,
+//     "[]": true,
+//   };
+//   const stack: string[] = [];
+//   for (const st of s) {
+//     if (
+//       !stack.length ||
+//       parentheses[`${stack[stack.length - 1]}${st}`] === undefined
+//     ) {
+//       stack.push(st);
+//     } else {
+//       stack.pop();
+//     }
+//   }
+//   return stack.length ? false : true;
+// }
+
+function isValid(s: string): boolean {
+  const parentheses: Record<string, string> = {
+    "(": ")",
+    "{": "}",
+    "[": "]",
+  };
+
+  const stack: string[] = [];
+  for (const char of s) {
+    if (parentheses[char]) {
+      stack.push(char);
+    } else {
+      const last = stack.pop();
+      if (last === undefined || parentheses[last] !== char) {
+        return false;
+      }
+    }
+  }
+
+  return !stack.length;
+}
+
+