字符串系列题目(C++)

参考链接：
https://leetcode-cn.com/problems/fan-zhuan-dan-ci-shun-xu-lcof/solution/yi-ge-mo-ban-shua-bian-suo-you-zi-fu-chu-x6vh/

class Solution {
public:
    int lengthOfLastWord(string s) {
        if(s.empty()){
            return 0;
        }
        s += " ";这里在最后一个字符位置加上空格，这样最后一个字符串就不会遗漏
        vectorres;
        string temp = "";
        for(char x:s){
            if(x == ' '){
                if(!temp.empty()){要不要判断非空取决于给定的字符串有没有前置或者后置的空格
                    res.push_back(temp);
                    temp.clear();
                }
            }else{
                temp += x;
            }
            
        }
        if(res.empty()){
            return 0;
        }
        return res.back().size();

    }
};

class Solution {
public:
    string reverseWords(string s) {
        if(s.empty()){
            return 0;
        }
        s += " ";
        vectorres;
        string temp = "";
        for(char x:s){
            if(x == ' '){
                res.push_back(temp);
                temp.clear(); 
            }else{
                temp += x;
            }
            
        }
        s.clear();
        for(string &m:res){
            reverse(m.begin(),m.end());
            s += m + ' ';
        }   
        s.pop_back(); //注意最后多加了一个空格要去掉   
        return s;
    }
};

class Solution {
public:
    string reverseWords(string s) {
        if(s.empty()){
            return "";
        }
        s += " ";
        vectorres;
        string temp = "";
        for(char x:s){
            if(x == ' '){
                if(!temp.empty()){
                    res.push_back(temp);
                    temp.clear();
                }              
            }else{
                temp += x;
            }
        }
        s.clear();
        reverse(res.begin(),res.end());
        for(string m:res){
            s += m + ' ';
        }
        s.pop_back();
        return s;
    }
};

class Solution {
public:
    string truncateSentence(string s, int k) {
        if(s.empty()){
            return "";
        }
        s+=" ";
        string temp = "";
        vectorres;
        for(char x:s){
            if(x == ' '){
                res.push_back(temp);
                temp.clear();
            }else{
                temp += x;
            }
        }
        
        s.clear();
        // int m = 0;
        // for(string &x:res){
        //     s += x + ' ';
        //     m++;
        //     if(m == k){
        //         break;
        //     }
        // }
        for(int  i =0;i < k;i++){
            s += res[i]+' ';
        }
        s.pop_back();
        return s;
    }
};

class Solution:
    def truncateSentence(self, s: str, k: int) -> str:
        return ' '.join(s.split(' ')[:k])

class Solution {
public:
    int numDifferentIntegers(string word) {
        sets;
        word += 'a';//以防止最后一个是数字
        string temp = "";
        for(char x:word){
            if(isalpha(x)){
                if(!temp.empty()){
                    s.insert(temp);//在集合中插入数字
                    temp.clear();
                }    
            }else{//遇到数字
                if(temp == "0"){//数字前导为0
                    temp.clear();
                }
                temp += x;
            }
        }
        return s.size();//集合去重，集合大小就是所有整数长度

    }
};

class Solution {
public:
    string mostCommonWord(string paragraph, vector& banned) {
        paragraph += " ";
        string temp = "";
        setban(banned.begin(),banned.end());
        maps;
        for(char x:paragraph){
            if(!isalpha(x)){
                if(!temp.empty()){
                    s[temp]++;//对每一个单词计数
                    temp.clear();
                }
                
            }else{
                temp += tolower(x);//转小写
            }
        }
        vectorwords;
        for(auto p:s){
            words.push_back(p.first);
        }
        sort(words.begin(),words.end(),[&](string &p,string &q){return s[p]>s[q];}); //按照频次降序
        if(ban.empty()){//如果没有禁用单词，直接返回排序后列表首元素
            return words[0];
        }
        for(auto w:words){
            if(ban.find(w) == ban.end()){
                return w;
            }
        }
        return "";
    }
};

class Solution {
public:
    string toGoatLatin(string sentence) {
        sentence += " ";
        string temp = "";
        vectorres;
        string vowels = "aeiouAEIOU";
        for(char x:sentence){
            if(x == ' '){
                res.push_back(temp);
                temp.clear();       
            }else{
                temp += x;
            }
        }
        sentence.clear();
        for(int i = 0; i