[lhc0506] WEEK 06 solutions

container-with-most-water/lhc0506.js

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+/**
+ * @param {number[]} height
+ * @return {number}
+ */
+var maxArea = function(height) {
+    let result = 0;
+    let left = 0;
+    let right = height.length - 1;
+
+    while(left < right) {
+        const leftHeight = height[left];
+        const rightHeight = height[right];
+        const width = right - left;
+
+        const minHeight = leftHeight < rightHeight ? leftHeight : rightHeight;
+        const area = minHeight * width;
+
+        if (area > result) {
+            result = area;
+        }
+
+        if (leftHeight <= rightHeight) {
+            left++;
+        } else {
+            right--;
+        }
+    }
+    return result;
+};
+
+// 시간 복잡도: O(n)
+// 공간 복잡도: O(1)

design-add-and-search-words-data-structure/lhc0506.js

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+const Node = function() {
+    this.children = {};
+    this.isEnd = false;
+}
+
+var WordDictionary = function() {
+    this.root = new Node();
+};
+
+/**
+ * @param {string} word
+ * @return {void}
+ */
+WordDictionary.prototype.addWord = function(word) {
+    let currentNode = this.root;
+
+    for (let char of word) {
+        if (!currentNode.children[char]) {
+            currentNode.children[char] = new Node();
+        }
+        currentNode = currentNode.children[char];
+    }
+
+    currentNode.isEnd = true;
+};
+
+/**
+ * @param {string} word
+ * @return {boolean}
+ */
+WordDictionary.prototype.search = function(word) {
+    if (word === undefined) return false;
+    return this._search(this.root, word, 0);
+};
+
+WordDictionary.prototype._search = function(node, word, index) {
+    if (index === word.length) {
+        return node.isEnd;
+    }
+
+    const char = word[index];
+
+    if (char !== '.') {
+        const child = node.children[char];
+        return child ? this._search(child, word, index + 1) : false;
+    }
+
+    for (const key in node.children) {
+        if (this._search(node.children[key], word, index + 1)) {
+            return true;
+        }
+    }
+
+    return false;
+};
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * var obj = new WordDictionary()
+ * obj.addWord(word)
+ * var param_2 = obj.search(word)
+ */
+
+// n: 단어수, m: 단어 길이
+// addWord: 시간 복잡도 O(m)
+// search: 	시간 복잡도 O(m)
+// 공간 복잡도 O(n * m)

longest-increasing-subsequence/lhc0506.js

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+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var lengthOfLIS = function(nums) {
+    const dp = new Array(nums.length).fill(1);
+
+    for (let i = 0; i < nums.length; i++) {
+        for (let j = 0; j < i; j++) {
+            if (nums[j] < nums[i] && dp[j] >= dp[i]) {
+                dp[i] = dp[j] + 1;
+            }
+        }
+    }
+
+    return Math.max(...dp);
+};
+
+// 시간 복잡도 : O(n^2)
+// 공간 복잡도 : O(n)

spiral-matrix/lhc0506.js

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+/**
+ * @param {number[][]} matrix
+ * @return {number[]}
+ */
+var spiralOrder = function(matrix) {
+   if (matrix.length === 0) return [];
+
+    const result = [];
+    const rows = matrix.length;
+    const cols = matrix[0].length;
+
+    let top = 0, bottom = rows - 1, left = 0, right = cols - 1;
+
+    while (top <= bottom && left <= right) {
+        for (let i = left; i <= right; i++) {
+            result.push(matrix[top][i]);
+        }
+        top += 1;
+
+        for (let i = top; i <= bottom; i++) {
+            result.push(matrix[i][right]);
+        }
+        right -= 1;
+
+        if (top <= bottom) {
+            for (let i = right; i >= left; i--) {
+                result.push(matrix[bottom][i]);
+            }
+            bottom -= 1;
+        }
+
+        if (left <= right) {
+            for (let i = bottom; i >= top; i--) {
+                result.push(matrix[i][left]);
+            }
+            left += 1;
+        }
+    }
+
+    return result;
+};

valid-parentheses/lhc0506.js

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+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+
+const BRACKETS = {
+    SMALL_LEFT : '(',
+    SMALL_RIGHT : ')',
+    MIDIDUM_LEFT : '{',
+    MIDIDUM_RIGHT : '}',
+    LARGE_LEFT : '[',
+    LARGE_RIGHT : ']',
+};
+
+const LEFT_BRAKCETS_SET = new Set([BRACKETS.SMALL_LEFT, BRACKETS.MIDIDUM_LEFT, BRACKETS.LARGE_LEFT]);
+
+const BRACKET_MAPPER = {
+    [BRACKETS.SMALL_RIGHT]: BRACKETS.SMALL_LEFT,
+    [BRACKETS.MIDIDUM_RIGHT]: BRACKETS.MIDIDUM_LEFT,
+    [BRACKETS.LARGE_RIGHT]: BRACKETS.LARGE_LEFT,
+};
+
+var isValid = function(s) {
+    const stack = [];
+
+    for (const bracket of s) {
+        if (LEFT_BRAKCETS_SET.has(bracket)) {
+            stack.push(bracket);
+        } else {
+            const poppedBracekt = stack.pop();
+
+            if (poppedBracekt !== BRACKET_MAPPER[bracket]) {
+                return false;
+            }
+        }
+    }
+
+    return stack.length === 0;
+};