Absolute Permutation, Algorithms

[prabaprakash]

Please list possible algo for solving these problems

[prabaprakash]

let permArr = [],
    usedChars = [];
function permute(input) {
    // console.log(input)
    var i, ch;
    for (i = 0; i < input.length; i++) {
        // fixed 1, then process [2,3]
        ch = input.splice(i, 1)[0];
        // usedchars [1]
        usedChars.push(ch);
        if (input.length == 0) {
            permArr.push(usedChars.slice());
        }
        // processing [2,3]
        permute(input);
        // 
        input.splice(i, 0, ch);
        usedChars.pop();
    }
    return permArr
};
process.stdout.write(JSON.stringify(permute([1, 2, 3])));

[prabaprakash]

Other methods recursive

function perm(xs) {
    let ret = [];

    for (let i = 0; i < xs.length; i++) {
        let currentChar = xs.splice(i, 1)[0];
        let rest = perm(xs);
        if (!rest.length) {
            ret.push([currentChar])
        } else {
            for (let j = 0; j < rest.length; j++) {
                ret.push([currentChar].concat(rest[j]))
            }
        }
        xs.splice(i, 0, currentChar);
    }

    return ret;
}

[prabaprakash]

Understanding question plays a major rule, these one is nothing to do with permutation.