String Permutations - Printable Version

String Permutations - Printable Version

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+--- Thread: String Permutations (/Thread-String-Permutations)

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RE: String Permutations - ArkPhaze - 08-24-2014

(08-22-2014, 03:06 PM)computerbug Wrote: this is an output for string "abc" .I can't understand why is space there in output instead a character?

Code:
acb a c bca b c cab c a
here is full c++ program

Code:
#include<iostream> #include<string> void swap(char* src,char * dest){ char ch=*src; *src=*dest; *dest=ch; } void permutation(std::string str,int start,int end){ if(end-start==1) std::cout<<str<<std::endl; else{ for(int i=start;i<end;i++){ swap(&str[start],&str[start+i]); permutation(str,start+1,end); swap(&str[start],&str[start+i]); } } } int main(){ std::string str; std::cout<<"enter any string = "; std::cin>>str; std::cout<<"you entered = "<<str<<std::endl; std::cout<<"length of string = "<<str.length()<<std::endl; permutation(str,0,str.length()); return 0; }

You're including the null terminator into the output...

RE: String Permutations - ArkPhaze - 08-24-2014

(08-22-2014, 03:06 PM)computerbug Wrote: this is an output for string "abc" .I can't understand why is space there in output instead a character?

Code:
acb a c bca b c cab c a
here is full c++ program

Code:
#include<iostream> #include<string> void swap(char* src,char * dest){ char ch=*src; *src=*dest; *dest=ch; } void permutation(std::string str,int start,int end){ if(end-start==1) std::cout<<str<<std::endl; else{ for(int i=start;i<end;i++){ swap(&str[start],&str[start+i]); permutation(str,start+1,end); swap(&str[start],&str[start+i]); } } } int main(){ std::string str; std::cout<<"enter any string = "; std::cin>>str; std::cout<<"you entered = "<<str<<std::endl; std::cout<<"length of string = "<<str.length()<<std::endl; permutation(str,0,str.length()); return 0; }

You're including the null terminator into the output...

RE: String Permutations - ArkPhaze - 08-24-2014

And you incorrectly modified the original code to do something improper for string permutations...

Code:
#include <iostream>
#include <string>

using namespace std;

void swap(char *src, char *dst)
{
  char ch = *dst;
  *dst = *src;
  *src = ch;
}

void permuteString(std::string s, int beg, int end)
{
  int range = end - beg;
  if (range == 1)
  {
    cout << s << endl;
    return;
  }
  for (int i = 0; i < range; i++)
  {
    swap(&s[beg], &s[beg + i]);
    permuteString(s, beg + 1, end);
    swap(&s[beg], &s[beg + i]);
  }

}

int main()
{
  std::string s = "123";
  permuteString(s, 0, s.length());
  return 0;
}

RE: String Permutations - ArkPhaze - 08-24-2014

And you incorrectly modified the original code to do something improper for string permutations...

Code:
#include <iostream>
#include <string>

using namespace std;

void swap(char *src, char *dst)
{
  char ch = *dst;
  *dst = *src;
  *src = ch;
}

void permuteString(std::string s, int beg, int end)
{
  int range = end - beg;
  if (range == 1)
  {
    cout << s << endl;
    return;
  }
  for (int i = 0; i < range; i++)
  {
    swap(&s[beg], &s[beg + i]);
    permuteString(s, beg + 1, end);
    swap(&s[beg], &s[beg + i]);
  }

}

int main()
{
  std::string s = "123";
  permuteString(s, 0, s.length());
  return 0;
}