使用 STL 对字符串进行排序

Question

I am trying to sort the characters of a string using C++ STL and came up with this code.

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>


int main() 
{
    using namespace std;
    vector<string>::iterator it;
    string arr[] = {"jajajaj"};
    vector<string> v(arr, arr+2);
    sort(v.begin(), v.end());
    for (it=v.begin(); it<v.end(); it++) {
      cout << *it;
   }
    return 0;
}

But unfortunately its not sorting properly when the array contains single element . How to do it using STL. Please help.

Answer 1

You can sort the string using std::string class.

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
int main()
{
     string str = "jajajaj";
     sort(str.begin(), str.end());
     cout << str;
     return 0;
}

Hope this might be helpful.

Answer 2

If you need a string, use a std::string :

(I used a for-range loop to make the code cleaner)

#include <iostream>
#include <algorithm>
#include <string>

using namespace std;

int main() 
{

    string s = {"jajajaj"};
    sort(s.begin(), s.end());
    for (auto c : s)
      cout << c;

    return 0;
}

Outputs :

aaajjjj

---

Note:

Your current code is not working because, as commented, you create a vector of size 2 out of an array of size 1, which has undefined behavior.

Answer 3

You seem to be confusing a std::string with an array of chars.

 int main() 
 {
     using namespace std;

     string arr = "jajajaj";
     vector<char> v(arr.begin(), arr.end());
     sort(v.begin(), v.end());
     vector<char>::iterator it;
     for (it=v.begin(); it<v.end(); ++it) {
       cout << *it;
    }
     return 0;
 }

I haven't tested that, but it should work....

UPDATE:

Alternately, we could just sort the string's character directly: (Thanks guys!)

 int main() 
 {
     using namespace std;

     string arr = "jajajaj";
     sort(arr.begin(), arr.end());
     cout << arr;
     return 0;
 }

Answer 4

You can use sort() function. sort() exists in algorithm header file

        #include<bits/stdc++.h>
        using namespace std;

        int main()
        {
            ios::sync_with_stdio(false);
            string str = "sharlock";

            sort(str.begin(), str.end());
            cout<<str<<endl;

            return 0;
        }

Output:

achklors

Answer 5

In order to sort a string, just input string from the user and use the sort() in STL for it.

   #include<bits/stdc++.h>
   using namespace std;

   int main()
   {
    string arr; 
    cin >>arr;
    sort(arr.begin(), arr.end());
    cout <<arr;
   }

See the sample image below for the output with input string as "Michael".