字符串的练习

#include<iostream>
#include<vector>
#include<string>
#include<map>

using namespace std;
struct TreeNode
{
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :val(x), left(NULL), right(NULL) {}
};

class IdenticalTree
{
public:
    string IntegertoStr(int m)
    {
        if(!m)
            return "0!";

        string res;
        vector<int> temp;
        while(m)
        {
            temp.push_back(m%10);
            m=m/10;
        }

        for(vector<int>::reverse_iterator riter=temp.rbegin();riter!=temp.rend();riter++)
            res.push_back(*riter+48);
        res.push_back(‘!‘);
        return res;
    }
    void Serialize(TreeNode* root,string &res)
    {
        //#==空值  !==值的结束符
        if(!root)
        {
            res+="#!";
            return;
        }
        res+=IntegertoStr((*root).val);
        Serialize((*root).left,res);
        Serialize((*root).right,res);
    }
    string toString(TreeNode* root)
    {
        string res;
        Serialize(root,res);
        return res;
    }
    bool chkIdentical(TreeNode* A, TreeNode* B)
    {
        //把两个二叉树序列化字符串
        string s1=toString(A),s2=toString(B);
        if(s1.find(s2)!=string::npos)
            return true;
        else
            return false;
    }
};

#include<iostream>
#include<string>
#include<vector>
using namespace std;
class Transform
{
public:
    bool chkTransform(string A, int lena, string B, int lenb)
    {
        if(lena!=lenb)
            return false;

        int HashTable1[256]={0},HashTable2[256]={0},i;
        for(i=0;i<lena;i++)
        {
            HashTable1[A[i]]++;
            HashTable2[B[i]]++;
        }

        i=0;
        while((i<256)&&HashTable1[i]==HashTable2[i])
            i++;

        if(i>=256)
            return true;
        else
            return false;
    }
};
int main()
{
    string a("abce"),b("rbca");
    Transform A;
    bool c=A.chkTransform(a,4,b,4);
    cout<<c;
    return 0;
}

#include<iostream>
#include<string>
#include<vector>
using namespace std;
//遇到字符串翻转的问题，一般都是先局部翻转然后整体翻转
class Translation
{
public:
    string stringTranslation(string A, int n, int len)
    {
        if(len>n)
            exit(-1);

        //1.先翻转0——len-1之间的字符
        reverseWord(A,0,len-1);
        //2.再翻转len——n-1之间的字符
        reverseWord(A,len,n-1);
        //3.然后整体翻转字符串
        reverseWord(A,0,n-1);
        return A;
    }
    void reverseWord(string &A,int low,int high)
    {
        if(low>=high)
            return;

        char temp;
        while(low<high)
        {
            temp=A[low];
            A[low]=A[high];
            A[high]=temp;
            low++;
            high--;
        }
    }
};
int main()
{
    string a("ABCDE");
    Translation A;
    string res=A.stringTranslation(a,5,3);
    cout<<res;
    return 0;
}

#include<iostream>
#include<string>
#include<vector>
using namespace std;
class Reverse
{
public:
    string reverseSentence(string A, int n)
    {
        if(A.empty())
            return "";

        reverseWord(A,0,n-1);

        //i记录单词的第一个字符，j记录单词的最后一个字符
        int i=0,j=0;
        while(i<n)
        {
            while(i<n&&A[i]==‘ ‘)
                i++;
            if(i>=n)
                return A;
            j=i;
            while(i<n&&A[i]!=‘ ‘)
                i++;
            if(i>=n)
            {
                reverseWord(A,j,n-1);
                return A;
            }
            reverseWord(A,j,i-1);
        }
        return A;
    }
    void reverseWord(string &A,int low,int high)
    {
        if(low>=high)
            return;

        char temp;
        while(low<high)
        {
            temp=A[low];
            A[low]=A[high];
            A[high]=temp;
            low++;
            high--;
        }
    }
};
int main()
{
    string arr("dog loves pig");
    Reverse a;
    a.reverseSentence(arr,13);
    cout<<arr;
    return 0;
}