Write out a function that prints out all the permutations of
a string.
For example, abc would give you abc, acb, bac, bca, cab,
cba. You can assume that all the characters will be unique.
- 5 Answers
- 21008 Views
- IITR, Microsoft, Nike, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / fallen angel
use plain recursion
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
void swap(char* src, char* dst)
{
char ch = *dst;
*dst = *src;
*src = ch;
}
/* permute [set[begin], set[end]) */
int permute(char* set, int begin, int end)
{
int i;
int range = end - begin;
if (range == 1) {
printf("set: %s\n", set);
} else {
for(i=0; i<range; i++) {
swap(&set[begin], &set[begin+i]);
permute(set, begin+1, end);
swap(&set[begin], &set[begin+i]);
/* set back */
}
}
return 0;
}
int main()
{
char str[] = "abcd";
permute(str, 0, strlen(str));
return 0;
}
| Is This Answer Correct ? | 28 Yes | 9 No |
Answer / patrick
//I think it can be implemented this way rather
simply..check it..
main(){
char a[15];
int len,fiblen,i,j,count=0,div,on,to;
printf("enter the string\n");
scanf("%s",a);
fiblen=fib(strlen(a));
div=fiblen/(strlen(a));
for(i=0;i<strlen(a);i++){
for(j=0;j<(strlen(a)-1);j++){
for(on=1;on<(strlen(a)-1);on++){
to=on+1;
swap(&a[on],&a[to]);
count++;//no: of anagram
printf("(%d) %s\n",count,a);
}
}
swap(&a[0],&a[i+1]);
}
}
swap(char *a,char *b){
char temp=*a;
*a=*b;
*b=temp;
}
int fib(int a){
if(a==1)
return(1);
else
return(a*fib(a-1));
}
| Is This Answer Correct ? | 4 Yes | 2 No |
Answer / raghuram.a
/*guys..I have implemented Jhonson trotter algorithm..u can
print permutations of 123..n. implement the same for strings!*/
#include<iostream.h>
#include<conio.h>
int min(int a[10],int n)
{
int i,m=1;
for(i=2;i<=n;i++)
{
if(a[m]>a[i])
m=i;
}
return m;
}
void swap(int &a,int &b)
{
int t;
t=a;
a=b;
b=t;
}
int main()
{
int i,j,k,n,flag=0,l,m;
int d[100],a[100];
clrscr();
cout<<"\n\nenter n:\n\n";
cin>>n;
for(i=1;i<=n;i++)
a[i]=i;
for(i=1;i<=n;i++)
d[i]=i-1;
cout<<"\n\npermutations generated for integer 12...n
are:\n\n";
for(i=1;i<=n;i++) //display the given no.
cout<<a[i];
cout<<"\t";
do
{
flag=0;
k=min(a,n);
for(i=1;i<=n;i++)
{
if((a[i]>a[k])&&(d[i]!=0)&&(a[d[i]]<a[i])) //find
mobile integer.
k=i;
}
if(a[k]==1)
break;
l=d[k]; //copy of direction of mobile integer.
m=a[k]; //copy of mobile integer.
if(d[k]==k+1&&d[k+1]==k) //swap directions.
{
if(d[k]==n)
{ d[k+1]=0;
d[k]=k-1;
}
else if(d[k+1]==1)
{
d[k]=0;
d[k+1]=k+2;
}
else
{ d[k]=k-1;
d[k+1]=k+2;
}
}
else if(d[k]==k-1&&d[k-1]==k)
{
d[k]=k+1;
d[k-1]=k-2;
}
/*cout<<d[1]<<d[2]<<d[3]<<d[4];
cout<<"\t";
if u want to know directions of integers.
*/
swap(a[k],a[l]); //swap mobile integer and integer it is
pointing to.
for(i=1;i<=n;i++)
cout<<a[i]; //display the number.
cout<<"\t";
for(i=1;i<=n;i++) //reverse directions of integers
greater than
//mobile integer.
{
if(a[i]>m)
{
if(d[i]==0&&i==n)
d[i]=i-1;
else if(d[i]<i)
d[i]=i+1;
else if(d[i]>i)
d[i]=i-1;
}
}
for(i=1;i<n;i++) //check whether a mobile integer exist or not.
{
if(a[i]<a[i+1])
{
if(d[i+1]!=0)
flag=1;
}
else if(a[i]>a[i+1])
{
if(d[i]!=0)
flag=1;
}
}
}
while(flag==1); //if no mobile
integer(flag=0)terminate the program.
getch();
return 0;
}
| Is This Answer Correct ? | 4 Yes | 3 No |
/*guys..I have implemented Jhonson trotter algorithm..u can
print permutations of 123..n. implement the same for strings!*/
#include<iostream.h>
#include<conio.h>
int min(int a[10],int n)
{
int i,m=1;
for(i=2;i<=n;i++)
{
if(a[m]>a[i])
m=i;
}
return m;
}
void swap(int &a,int &b)
{
int t;
t=a;
a=b;
b=t;
}
int main()
{
int i,j,k,n,flag=0,l,m;
int d[100],a[100];
clrscr();
cout<<"\n\nenter n:\n\n";
cin>>n;
for(i=1;i<=n;i++)
a[i]=i;
for(i=1;i<=n;i++)
d[i]=i-1;
cout<<"\n\npermutations generated for integer 12...n
are:\n\n";
for(i=1;i<=n;i++) //display the given no.
cout<<a[i];
cout<<"\t";
do
{
flag=0;
k=min(a,n);
for(i=1;i<=n;i++)
{
if((a[i]>a[k])&&(d[i]!=0)&&(a[d[i]]<a[i])) //find
mobile integer.
k=i;
}
if(a[k]==1)
break;
l=d[k]; //copy of direction of mobile integer.
m=a[k]; //copy of mobile integer.
if(d[k]==k+1&&d[k+1]==k) //swap directions.
{
if(d[k]==n)
{ d[k+1]=0;
d[k]=k-1;
}
else if(d[k+1]==1)
{
d[k]=0;
d[k+1]=k+2;
}
else
{ d[k]=k-1;
d[k+1]=k+2;
}
}
else if(d[k]==k-1&&d[k-1]==k)
{
d[k]=k+1;
d[k-1]=k-2;
}
/*cout<<d[1]<<d[2]<<d[3]<<d[4];
cout<<"\t";
if u want to know directions of integers.
*/
swap(a[k],a[l]); //swap mobile integer and integer it is
pointing to.
for(i=1;i<=n;i++)
cout<<a[i]; //display the number.
cout<<"\t";
for(i=1;i<=n;i++) //reverse directions of integers
greater than
//mobile integer.
{
if(a[i]>m)
{
if(d[i]==0&&i==n)
d[i]=i-1;
else if(d[i]<i)
d[i]=i+1;
else if(d[i]>i)
d[i]=i-1;
}
}
for(i=1;i<n;i++) //check whether a mobile integer exist or not.
{
if(a[i]<a[i+1])
{
if(d[i+1]!=0)
flag=1;
}
else if(a[i]>a[i+1])
{
if(d[i]!=0)
flag=1;
}
}
}
while(flag==1); //if no mobile
integer(flag=0)terminate the program.
getch();
return 0;
}
| Is This Answer Correct ? | 5 Yes | 5 No |
Answer / shikha
#include <iostream>
using namespace std;
void anagram(char x[],string temp){
int size = 0;
while(x[size] != '\0'){
size++;
}
// cout << size << " " << x << endl;
if(size > 0){
for(int i=0; i<size ; i++){
string temp1 = temp + x[i];
char y[size];
for(int j=0,k=0; j<size-1 ; j++,k++){
if(k != i) y[j] = x[k];
else j--;
}
y[size-1] = '\0';
anagram(y,temp1);
}
}
else{
cout << temp << endl;
temp = "";
}
}
int main(){
char name[] = "abc";
anagram(name, "");
return 0;
}
| Is This Answer Correct ? | 1 Yes | 2 No |
write a c-program to display the time using FOR loop
what is the output of the below program & why ? #include<stdio.h> void main() { int a=10,b=20,c=30; printf("%d",scanf("%d%d%d",&a,&b,&c)); }
int swap(int *a,int *b) { *a=*a+*b;*b=*a-*b;*a=*a-*b; } main() { int x=10,y=20; swap(&x,&y); printf("x= %d y = %d\n",x,y); }
void main() { int c; c=printf("Hello world"); printf("\n%d",c); }
find A^B using Recursive function
how can i cast a char type array to an int type array
Question: We would like to design and implement a programming solution to the reader-writer problem using semaphores in C language under UNIX. We assume that we have three readers and two writers processes that would run concurrently. A writer is to update (write) into one memory location (let’s say a variable of type integer named temp initialized to 0). In the other hand, a reader is to read the content of temp and display its content on the screen in a formatted output. One writer can access the shared data exclusively without the presence of other writer or any reader, whereas, a reader may access the shared memory for reading with the presence of other readers (but not writers).
main() { int i; clrscr(); for(i=0;i<5;i++) { printf("%d\n", 1L << i); } } a. 5, 4, 3, 2, 1 b. 0, 1, 2, 3, 4 c. 0, 1, 2, 4, 8 d. 1, 2, 4, 8, 16
Is the following code legal? typedef struct a aType; struct a { int x; aType *b; };
There are 21 people in a room. They have to form groups of 3 people each. How many combinations are possible? Write a C program to print the same.
#define a 10 void foo() { #undef a #define a 50 } int main() { printf("%d..",a); foo(); printf("%d..",a); return 0; } explain the answer
#include <stdio.h> #define a 10 main() { #define a 50 printf("%d",a); }
C Code 
