Find all the combinations of a string Javascript

Question

I want to find all the combinations of a string in javascript. I looked up previously asked questions but there is one output missing and I don't know how to find it.

My code is:

    <html>

    <head></head>

    <body>

    <label>Enter word/sentence to generate combinations:</label>

        <input type="text" name="comb"/></br>

        <input type="button" value="Get Combination" name="combbtn" onclick="substrings()"/>

        <script>

            function substrings(){

                var str=document.getElementsByTagName("input")[0].value;

                var i, j, result = [];

                  for (i = 0; i < str.length; i++) {

                      for (j = i + 1; j < str.length + 1; j++) {

                          result.push(str.slice(i, j));

                      }

                  }

                  alert(result);

            }

        </script>

    </body>

</html>

When I try "dad" as input, the expected output is:-

d,a,da,d,dd,ad,dad

But my code somehow misses

"dd"

How can I include it. Any help/suggestion?

Recommended for you: Get network issues from WhatsUp Gold. Not end users.

Answer 1

what you need to do is print all subsequences, this code would do that

function printSubsequences(str){
    let len = str.length, result = [];
    for(let i=1; i<(1<<len); i++){
        let temp = "";
        for(let j=0; j<len; j++){
            if((i&(1<<j))){
                temp = temp +str.charAt(j);
            }
        }
        result.push(temp);
    }
    console.log(result);
}
printSubsequences('dad');

Note the time complexity is exponential

Find all the combinations of a string Javascript

Sign up