Question

Use C++

Given a set of characters in an array, write a program to print all permutations (with duplications allowed) using pointers. For example: If given string char str[] = "CMPT": The expected output is "CMPT CMTP CPMT CPTM CTPM CTMP MCPT MCTP MPCT MPTC MTPC MTCP PMCT PMTC PCMT PCTM PTCM PTMC TMPC TMCP TPMC TPCM TCPM TCMP"

Answer 1

C++:

#include <iostream>

using namespace std;

void swap(char *x, char *y){

char temp;

temp=*x;

*x=*y;

*y=temp;

}

void permuteString(char *a,int sIndex, int eIndex) {

if(sIndex==eIndex)

cout<<a<<" ";

else{

//swap characters

for(int i=sIndex;i<=eIndex;i++){

swap(a+sIndex,a+i) ;

//for each swap permute new string

//again

permuteString(a, sIndex+1,eIndex);

//swap back to retain original string

swap(a+sIndex,a+i);

}

}

}

int main() {

char str[] ="CMPT";

permuteString(str, 0,3);

}

Output: