Merge pull request #90 from AlgorithmIsMyLife/27일차_Jongeun

Add day27

Author: summer2788

Jongeun/Day27/133_CloneGraph.cpp

@@ -0,0 +1,76 @@
+/*
+// Definition for a Node.
+class Node {
+public:
+    int val;
+    vector<Node*> neighbors;
+    Node() {
+        val = 0;
+        neighbors = vector<Node*>();
+    }
+    Node(int _val) {
+        val = _val;
+        neighbors = vector<Node*>();
+    }
+    Node(int _val, vector<Node*> _neighbors) {
+        val = _val;
+        neighbors = _neighbors;
+    }
+};
+*/
+
+class Solution
+{
+public:
+    Node *cloneGraph(Node *node)
+    {
+        vector<Node *> nodes(101, nullptr);
+        vector<bool> visited(101, false);
+        queue<Node *> q;
+        q.push(node);
+
+        if (node == nullptr)
+        {
+            return nullptr;
+        }
+
+        while (!q.empty())
+        {
+            Node *cur = q.front();
+            q.pop();
+            vector<Node *> cpNeighbors;
+
+            for (auto n : cur->neighbors)
+            {
+                if (!visited[n->val])
+                {
+                    q.push(n);
+                    if (!nodes[n->val])
+                    {
+                        // Not exist
+                        Node *temp = new Node(n->val);
+                        nodes[n->val] = temp;
+                    }
+                }
+
+                // Add a neighbor
+                cpNeighbors.push_back(nodes[n->val]);
+            }
+
+            if (!nodes[cur->val])
+            {
+                // not existed
+                Node *newNode = new Node(cur->val, cpNeighbors);
+                nodes[cur->val] = newNode;
+                visited[cur->val] = true;
+            }
+            else
+            {
+                nodes[cur->val]->neighbors = cpNeighbors;
+                visited[cur->val] = true;
+            }
+        }
+
+        return nodes[1];
+    }
+};

Jongeun/Day27/198_HouseRobber.cpp

@@ -0,0 +1,16 @@
+class Solution
+{
+public:
+    int rob(vector<int> &nums)
+    {
+        int first = 0, second = 0;
+        for (int i = 0; i < nums.size(); i++)
+        {
+            int tempt = first;
+            first = second;
+            second = max(second, tempt + nums[i]);
+        }
+
+        return second;
+    }
+};

Jongeun/Day27/55_JumpGame.cpp

@@ -0,0 +1,27 @@
+class Solution
+{
+public:
+    bool canJump(vector<int> &nums)
+    {
+        int l = 0;
+        int maxIndex = 0;
+
+        while (l < nums.size() - 1)
+        {
+            maxIndex = max(maxIndex, l + nums[l]);
+            if (maxIndex >= nums.size() - 1)
+            {
+                return true;
+            }
+
+            if (l == maxIndex)
+            {
+                return false;
+            }
+
+            l++;
+        }
+
+        return true;
+    }
+};