Merge branch 'DaleStudy:main' into main

Author: sadie100

3sum/gcount85.py 3sum/jamiebase.py3sum/gcount85.py renamed to 3sum/jamiebase.py

@@ -0,0 +1,26 @@
+function maxProfit(prices: number[]): number {
+  let minPrice = Number.MAX_SAFE_INTEGER;
+  let maxProfit = 0;
+
+  for (let p of prices) {
+    if (minPrice >= p) {
+      minPrice = p;
+      continue;
+    } else {
+      let profit = p - minPrice;
+      if (profit > maxProfit) maxProfit = profit;
+    }
+  }
+  return maxProfit;
+}
+
+function maxProfit(prices: number[]): number {
+  let minPrice = Infinity;
+  let maxProfit = 0;
+
+  for (let p of prices) {
+    minPrice = Math.min(minPrice, p);
+    maxProfit = Math.max(maxProfit, p - minPrice);
+  }
+  return maxProfit;
+}

3sum/soobing3.ts 3sum/soobing.ts3sum/soobing3.ts renamed to 3sum/soobing.ts

@@ -23,7 +23,6 @@ var maxProfit = function (prices) {
     return maxProfit;
 };
 
-
 // -----아래는 이전에 작성한 답안입니다.
 // /**
 //  * @param {number[]} prices

best-time-to-buy-and-sell-stock/hyejj19.ts

@@ -1,14 +1,16 @@
+// 3rd tried
 function maxProfit(prices: number[]): number {
-  let minPrice = Infinity;
-  let maxProfit = 0;
-  for (let i = 0; i < prices.length; i++) {
-    if (prices[i] < minPrice) {
-      minPrice = prices[i];
-    }
+  let left = 0;
+  let right = 1;
+  let max = 0;
 
-    if (prices[i] - minPrice > maxProfit) {
-      maxProfit = prices[i] - minPrice;
-    }
+  while(left < right && right < prices.length) {
+      if(prices[right] - prices[left] > 0) {
+          max = Math.max(max, prices[right] - prices[left])
+      } else {
+          left = right;
+      }
+      right++;
   }
-  return maxProfit;
-}
+  return max;
+};

…t-time-to-buy-and-sell-stock/gcount85.py …-time-to-buy-and-sell-stock/jamiebase.pybest-time-to-buy-and-sell-stock/gcount85.py renamed to best-time-to-buy-and-sell-stock/jamiebase.py best-time-to-buy-and-sell-stock/gcount85.py renamed to best-time-to-buy-and-sell-stock/jamiebase.py

@@ -1,34 +1,14 @@
-/**
- * 문제 유형
- * - DP (피보나치)
- *
- * 문제 설명
- * - 계단을 올라가는 방법의 수를 구하기
- *
- * 아이디어
- * 1) 피보나치 수열 활용
- * - climbStairs(n) = climbStairs(n-1) + climbStairs(n-2)
- */
-function climbStairsBottomUp(n: number): number {
-  function fibonacci(n: number, memo = new Map<number, number>()) {
-    if (n === 1) return 1;
-    if (n === 2) return 2;
+function climbStairs(n: number): number {
+  const memo = new Map<number, number>();
+  
+  function dp (n: number): number {
+      if(n <= 1) return 1;
+      if(memo.has(n)) return memo.get(n)!;
 
-    if (memo.has(n)) return memo.get(n);
-    const result = fibonacci(n - 1, memo) + fibonacci(n - 2, memo);
-    memo.set(n, result);
-    return result;
+      const result = dp(n-1) + dp(n-2);
+      memo.set(n, result);
+      return result;
   }
-  return fibonacci(n);
-}
 
-function climbStairsTopDown(n: number): number {
-  const dp = new Array(n + 1).fill(0);
-  dp[1] = 1;
-  dp[2] = 2;
-
-  for (let i = 3; i <= n; i++) {
-    dp[i] = dp[i - 1] + dp[i - 2];
-  }
-  return dp[n];
-}
+  return dp(n);
+};

best-time-to-buy-and-sell-stock/robinyoon-dev.js

@@ -0,0 +1,48 @@
+import java.util.*;
+/*
+class Node {
+    public int val;
+    public List<Node> neighbors;
+    public Node() {
+        val = 0;
+        neighbors = new ArrayList<Node>();
+    }
+    public Node(int _val) {
+        val = _val;
+        neighbors = new ArrayList<Node>();
+    }
+    public Node(int _val, ArrayList<Node> _neighbors) {
+        val = _val;
+        neighbors = _neighbors;
+    }
+}
+*/
+
+
+class Solution {
+
+
+    //기존 node, 복사한 node
+    Map<Node, Node> visited = new HashMap<>();
+    public Node cloneGraph(Node node) {
+        if (node==null) return null;
+
+        if (visited.containsKey(node)){
+            return visited.get(node);
+        }
+
+        //없는 경우
+        Node newClone= new Node(node.val);
+        visited.put(node, newClone);
+
+        //이웃 복사
+        for(Node target : node.neighbors){
+            newClone.neighbors.add(cloneGraph(target));
+        }
+
+        return newClone;
+
+    }
+}
+
+