1)Pseudocode:-
Prompt user to enter string
Pass it to combination function which can calculate the entire combination and can return it in an array
In combination method -
Check if the string is length 2 size ie of 0 or 1 length then return string itself
Else iterate through string user entered
Get the present character within the variable and check if the variable is already used then skip
Create a string from 0 to i the index + (concatenate) i+1 to length and recursive call combination function and pass this string and store end in subpermutation array
For each recursive call push character + sub permutation in total arrangement array.
2)Code -
function combinations(userStr) {
/* when string length is less than 2 then simply return string */
if (userStr.length < 2) return userStr;
/* this array will store number of arrangement that word can be stored */
var totalArrangements = [];
/* iterate through string user enter */
for (var i = 0; i < userStr.length; i++) {
/* get the current character */
var character = userStr[i];
/*check if character is already used than skip */
if (userStr.indexOf(character) != i)
continue;
/* create a string and concanete it form 0 to i index and i+1 to length of array */
var str = userStr.slice(0, i) + userStr.slice(i + 1, userStr.length);
/* push it to totalArrangments */
for (var subPermutation of combinations(str))
totalArrangements.push(character + subPermutation)
}
/* return the total arrangements */
return totalArrangements;
}
/* ask user to prompt string */
var userStr = prompt("Enter a string: ");
/* count to count the total number of combinations */
let count = 0;
/* call function the return tolal number of arrangement in array */
totalArrangements = combinations(userStr);
/* print the combination in console */
for (permutation of totalArrangements) {
console.log(permutation)
}
/* total combination will be totalArrangements.length */
count = totalArrangements.length;
/*print it to console */
console.log("Total combination " + count)
Output:-
