Add June Week 1

JuneChallenge/Week1/1:InvertBinaryTree.cpp

@@ -0,0 +1,23 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ * int val;
+ * TreeNode *left;
+ * TreeNode *right;
+ * TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ * TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+ TreeNode* invertTree(TreeNode* root) {
+ if (root == nullptr) return root;
+ TreeNode* temp = root->left;
+ root->left = root->right;
+ root->right = temp;
+ invertTree(root->left);
+ invertTree(root->right);
+ return root;
+ }
+};

JuneChallenge/Week1/2:DeleteNodeinaLinkedList.cpp

@@ -0,0 +1,19 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ * int val;
+ * ListNode *next;
+ * ListNode(int x) : val(x), next(NULL) {}
+ * };
+ */
+class Solution {
+public:
+ void deleteNode(ListNode* node) {
+ while(node->next->next != nullptr) {
+ node->val = node->next->val;
+ node = node->next;
+ }
+ node->val = node->next->val;
+ node->next = nullptr;
+ }
+};

JuneChallenge/Week1/3:TwoCityScheduling.cpp

@@ -0,0 +1,17 @@
+class Solution {
+public:
+ static bool comparator(vector<int> a, vector<int> b) {
+ return (a[0]-a[1]) < (b[0]-b[1]);
+ }
+ int twoCitySchedCost(vector<vector<int>>& costs) {
+ int n = costs.size()/2;
+ int ans = 0;
+ sort(costs.begin(), costs.end(), comparator);
+ for (int i = 0; i < n; i++) {
+ ans += costs[i][0];
+ ans += costs[i + n][1];
+ }
+ return ans;
+ }
+};
+

JuneChallenge/Week1/4:ReverseString.cpp

@@ -0,0 +1,15 @@
+class Solution {
+public:
+ void reverseString(vector<char>& s) {
+ int n = s.size();
+ int first = 0, second = n - 1;
+ while (first <= second) {
+ char temp = s[first];
+ s[first] = s[second];
+ s[second] = temp;
+ first++;
+ second--;
+ }
+ }
+};
+

JuneChallenge/Week1/5:RandomPickwithWeight.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+ vector<int> weight;
+ int total = 0;
+ Solution(vector<int>& w) {
+ srand(time(NULL));
+ for (int i = 0; i < w.size(); i++) {
+ total += w[i];
+ weight.push_back(total);
+ }
+ }
+ int pickIndex() {
+ int ind = rand() % weight.back();
+ return upper_bound(weight.begin(), weight.end(), ind) - weight.begin();
+ }
+};
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * Solution* obj = new Solution(w);
+ * int param_1 = obj->pickIndex();
+ */

JuneChallenge/Week1/6:QueueReconstructionbyHeight.cpp

@@ -0,0 +1,17 @@
+class Solution {
+public:
+ static bool comparator(vector<int> a, vector<int> b){
+ if (a[0] == b[0])
+ return a[1] > b[1];
+ return a[0] < b[0];
+ }
+ vector<vector<int>> reconstructQueue(vector<vector<int>>& people) {
+ sort(people.begin(), people.end(), comparator);
+ vector <vector<int>> ans;
+ for(int i = people.size() - 1; i >= 0; i--){
+ ans.insert(ans.begin() + people[i][1], people[i]);
+ }
+ return ans;
+ }
+};
+

JuneChallenge/Week1/7:CoinChange2.cpp

@@ -0,0 +1,13 @@
+class Solution {
+public:
+ int change(int amount, vector<int>& coins) {
+ int n = coins.size();
+ vector<int> dp(amount + 1, 0);
+ dp[0] = 1;
+ for(int i = 0; i < n; i++) 
+ for(int j = coins[i]; j <= amount; j++) 
+ dp[j] += dp[j - coins[i]]; 
+ return dp[amount];
+ }
+};
+

README.md

@@ -2,27 +2,29 @@
 
 ## My Leetcode submissions, primarily in C++
 
-- Files contain only the solution class provided by the platform.
+-  Files contain only the solution class provided by the platform.
 
-- I make all submissions from [this profile](https://leetcode.com/thepushkarp/).
+-  I make all submissions from [this profile](https://leetcode.com/thepushkarp/).
 
 ## Contents
 
-- [leetcode](#leetcode)
- - [My Leetcode submissions, primarily in C++](#my-leetcode-submissions-primarily-in-c)
- - [Contents](#contents)
- - [April 30 Day Challenge](#april-30-day-challenge)
- - [Week 1](#week-1)
- - [Week 2](#week-2)
- - [Week 3](#week-3)
- - [Week 4](#week-4)
- - [Week 5](#week-5)
- - [May Challenge](#may-challenge)
- - [Week 1](#week-1-1)
- - [Week 2](#week-2-1)
- - [Week 3](#week-3-1)
- - [Week 4](#week-4-1)
- - [Week 5](#week-5-1)
+- [leetcode](#leetcode)
+ - [My Leetcode submissions, primarily in C++](#my-leetcode-submissions-primarily-in-c)
+ - [Contents](#contents)
+ - [April 30 Day Challenge](#april-30-day-challenge)
+ - [Week 1](#week-1)
+ - [Week 2](#week-2)
+ - [Week 3](#week-3)
+ - [Week 4](#week-4)
+ - [Week 5](#week-5)
+ - [May Challenge](#may-challenge)
+ - [Week 1](#week-1-1)
+ - [Week 2](#week-2-1)
+ - [Week 3](#week-3-1)
+ - [Week 4](#week-4-1)
+ - [Week 5](#week-5-1)
+ - [June Challenge](#june-challenge)
+ - [Week 1](#week-1-2)
 
 ## April 30 Day Challenge
 
@@ -140,3 +142,17 @@ Since I am completing this in May, I could not access the 7th question of each w
 | 29 | [Course Schedule](MayChallenge/Week5/29:CourseSchedule.cpp) |
 | 30 | [K Closest Points to Origin](MayChallenge/Week5/30:KClosestPointstoOrigin.cpp) |
 | 31 | [Edit Distance](MayChallenge/Week5/31:EditDistance.cpp) |
+
+## June Challenge
+
+### Week 1
+
+| Day | Name |
+| --- | --------------------------------------------------------------------------------------- |
+| 1 | [Invert Binary Tree](JuneChallenge/Week1/1:InvertBinaryTree.cpp) |
+| 2 | [Delete Node in a Linked List](JuneChallenge/Week1/2:DeleteNodeinaLinkedList.cpp) |
+| 3 | [Two City Scheduling](JuneChallenge/Week1/3:TwoCityScheduling.cpp) |
+| 4 | [Reverse String](JuneChallenge/Week1/4:ReverseString.cpp) |
+| 5 | [Random Pick with Weight](JuneChallenge/Week1/5:RandomPickwithWeight.cpp) |
+| 6 | [Queue Reconstruction by Height](JuneChallenge/Week1/6:QueueReconstructionbyHeight.cpp) |
+| 7 | [Coin Change 2](JuneChallenge/Week1/7:CoinChange2.cpp) |