zhangxiaomu01

class Solution {
public:
    int maxArea(vector<int>& height) {
        int len = height.size();
        int l = 0, r = len-1, maxArea = 0;   
        while(l<r)
        {
            if(height[l] <= height[r])
            {
               

zhangxiaomu01

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int len_s = strs.size();
        if(len_s == 0) return "";
        
        for(int j = 0; j < strs[0].size(); j++){ 
            char c = strs[0][j];
            for(int i = 0; i < len_s; i++){
                //Basically we check two cases:

zhangxiaomu01

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int len_s = strs.size();
        if(len_s == 0) return "";
        
        string prefix = strs[0];
        for(int i = 1; i < len_s; i++){ 
            int minlen = min(prefix.size(), strs[i].size());
            

zhangxiaomu01

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int len_s = strs.size();
        if(len_s == 0) return "";
        return longestCommonPrefix(strs, 0, len_s - 1);
    }
    string longestCommonPrefix(vector<string>& strs, int l, int r){
        if(l == r){
            return strs[l];

zhangxiaomu01

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int len = strs.size();
        string finalStr;
        if(len == 0) return "";
        sort(strs.begin(), strs.end());
        int n = strs[0].size();
        for(int i = 0; i<n; i++)
        {

zhangxiaomu01

class Solution {
public:
    vector<vector<int>> threeSum(vector<int>& nums) {
        int len = nums.size();
        vector<vector<int>> finalResult;
        std::sort(nums.begin(), nums.end());
        if(len <= 2)
            return finalResult;
        
        for(int i = 0; i < len - 2; i++)

zhangxiaomu01

class Solution {
public:
    int threeSumClosest(vector<int>& nums, int target) {
        int sub = INT_MAX;
        int sum = 0;
        int len = nums.size();
        for(int i = 0; i < len; i++){
            for(int j = i+1; j < len; j++){
                for(int k = j+ 1; k < len; k++){
                    if(abs(nums[i]+nums[j]+nums[k] - target) < sub){

zhangxiaomu01

class Solution {
public:
    int threeSumClosest(vector<int>& nums, int target) {
        std::sort(nums.begin(), nums.end());
        int len = nums.size();
        long bestDist = LONG_MAX, bestSum = target; 
        if(len <= 2) 
            return 0;
        
        for(int i = 0; i < len-2; i++)

zhangxiaomu01

class Solution {
public:
    vector<vector<int>> fourSum(vector<int>& nums, int target) {
        vector<vector<int>> finalResult;
        int len = nums.size();
        if(len <= 3)
            return finalResult;
        else
            sort(nums.begin(), nums.end());
        

zhangxiaomu01

class Solution {
private:
    vector<string> dic_s = {"", "", "abc", "def", "ghi","jkl", "mno","pqrs", "tuv", "wxyz"};
    vector<string> result;
public:
    void dfs(const string &digits, string s, int pos){
        int len = digits.size();
        if(pos >= len){
            return;
        }