SeoGeonhyuk / 3주차, 4주차 / 2문제

.gitignore

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+.DS_Store
+SeoGeonhyuk/.DS_Store

SeoGeonhyuk/dynamic_programming/integertriangle.js

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+let answer = 0;
+function maxPathCalculator(floorArray, arrays){
+    if(arrays.length === 0){
+        floorArray.forEach((num) => {
+            if (answer <= num)
+                answer = num;
+        })
+    }
+    else{
+        const partArray = arrays.shift();
+        const futureFloorArray = new Array(partArray.length).fill(0);
+        for(let i = 0; i < floorArray.length; i++){
+            const possiblePathSum = floorArray[i] + partArray[i];
+            if(possiblePathSum > futureFloorArray[i])
+                futureFloorArray[i] = possiblePathSum;
+            if(i + 1 < partArray.length)
+                futureFloorArray[i + 1] = (floorArray[i] + partArray[i + 1]);
+        }
+        maxPathCalculator(futureFloorArray, arrays);
+    }
+}
+function solution(triangle) {
+    const oldSum = triangle[0][0];
+    triangle.shift();
+    maxPathCalculator([oldSum], triangle);
+    return answer;
+}

SeoGeonhyuk/heap/morehot.js

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+class MinHeap {
+    constructor() {
+        this.heap = [];
+    }
+
+    getParentIndex(index) {
+        return Math.floor((index - 1) / 2);
+    }
+
+    getLeftChildIndex(index) {
+        return index * 2 + 1;
+    }
+
+    getRightChildIndex(index) {
+        return index * 2 + 2;
+    }
+
+    insert(value) {
+        this.heap.push(value);
+        this.heapifyUp();
+    }
+
+    heapifyUp() {
+        let index = this.heap.length - 1;
+        while (index > 0) {
+            let parentIndex = this.getParentIndex(index);
+            if (this.heap[parentIndex] > this.heap[index]) {
+                [this.heap[parentIndex], this.heap[index]] = [this.heap[index], this.heap[parentIndex]];
+                index = parentIndex;
+            } else {
+                break;
+            }
+        }
+    }
+
+    extractMin() {
+        if (this.heap.length === 1) return this.heap.pop();
+        const min = this.heap[0];
+        this.heap[0] = this.heap.pop();
+        this.heapifyDown();
+        return min;
+    }
+
+    heapifyDown() {
+        let index = 0;
+        while (this.getLeftChildIndex(index) < this.heap.length) {
+            let smallerChildIndex = this.getLeftChildIndex(index);
+            if (this.getRightChildIndex(index) < this.heap.length && this.heap[this.getRightChildIndex(index)] < this.heap[smallerChildIndex]) {
+                smallerChildIndex = this.getRightChildIndex(index);
+            }
+            if (this.heap[index] > this.heap[smallerChildIndex]) {
+                [this.heap[index], this.heap[smallerChildIndex]] = [this.heap[smallerChildIndex], this.heap[index]];
+                index = smallerChildIndex;
+            } else {
+                break;
+            }
+        }
+    }
+
+    size() {
+        return this.heap.length;
+    }
+
+    peek() {
+        return this.heap[0];
+    }
+}
+
+function solution(scoville, K) {
+    const minHeap = new MinHeap();
+    scoville.forEach(num => minHeap.insert(num));
+
+    let answer = 0;
+
+    while (minHeap.size() > 1 && minHeap.peek() < K) {
+        let first = minHeap.extractMin();
+        let second = minHeap.extractMin();
+        let newScoville = first + (second * 2);
+        minHeap.insert(newScoville);
+        answer++;
+    }
+
+    if (minHeap.peek() < K) {
+        return -1;
+    }
+
+    return answer;
+}