Jun Zhang zhangxiaomu01

## LetterCombinationsPhone_Mul.cpp
class Solution {
private:
    vector<string> strDic = {"", "", "abc", "def", "ghi","jkl", "mno","pqrs", "tuv", "wxyz"};
    vector<string> finalVec;
public:
    vector<string> letterCombinations(string digits) {
        int len_d = digits.length();

        for(int i = 0; i < len_d; i++){
            int index = digits[i] - '0';

## RemoveNthNode_BF.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## RemoveNthNode_TwoPointers.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## GenerateParentheses_BackTracing.cpp
vector<string>res;
class Solution {
public:
    void choose(string prix,int left,int right,int times,int num){
        if(times==num){
            string temp =prix+")";
            res.push_back(temp);
            return;
        }
        if(left<num/2){

## GenerateParentheses_Permutation.cpp
class Solution {
public:
    vector<string> generateParenthesis(int n) {
        vector<string> res;
        if(n == 0)
            res.push_back("");
        else{
            for(int left = 0; left < n; left++){
                vector<string> tempL = generateParenthesis(left);
                for(int i = 0; i< tempL.size(); i++){

## MergeKSortedLists_BF.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## MergeKSortedLists_CColunmn.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## MergeKSortedLists_Pqueue.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## MergeKSortedLists_MergeTwo.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

## SwapNodesinPairs_RSwap.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
	class Solution {
	private:
	vector<string> strDic = {"", "", "abc", "def", "ghi","jkl", "mno","pqrs", "tuv", "wxyz"};
	vector<string> finalVec;
	public:
	vector<string> letterCombinations(string digits) {
	int len_d = digits.length();

	for(int i = 0; i < len_d; i++){
	int index = digits[i] - '0';
	/**
	* Definition for singly-linked list.
	* struct ListNode {
	* int val;
	* ListNode *next;
	* ListNode(int x) : val(x), next(NULL) {}
	* };
	*/
	class Solution {
	public:
	vector<string>res;
	class Solution {
	public:
	void choose(string prix,int left,int right,int times,int num){
	if(times==num){
	string temp =prix+")";
	res.push_back(temp);
	return;
	}
	if(left<num/2){
	class Solution {
	public:
	vector<string> generateParenthesis(int n) {
	vector<string> res;
	if(n == 0)
	res.push_back("");
	else{
	for(int left = 0; left < n; left++){
	vector<string> tempL = generateParenthesis(left);
	for(int i = 0; i< tempL.size(); i++){