Optimizing code solution for Palindrome Index-Hackerrank

Question

I submitted my solution for palindrome Index coding challenge but I get "test cases terminated due to time out error". My code is working and so I don't know what else to do to optimize it. Please help:

function palindromeIndex(s) {
 let palindrome = s === s.split('').reverse().join('')
 if(!palindrome) {
 let i = 0
 let integerIndex = []
 let arr = s.split('')
 while(i < s.length) {
 arr.splice(i,1)
 if(arr.join('') === arr.reverse().join('')) {
 integerIndex.push(i) 
 }
 arr = s.split('')
 i++
 }
 return integerIndex.length > 0 ? integerIndex[0] : - 1
 }else {
 return -1
 }
}

• pacmaninbw: Could you please add the text of the question and a link to the coding challenge to the body of this question? We need the exact specification of the coding challenge.

Answer 1

It may well be an error @ Hackerrank. If I'm not mistaken the nodejs-code expects you to provide console input. Or you may have accidentally changed something in the surrounding code.

Concerning your code: writing ES20xx, it's good practice to terminate lines with a semicolon (;), because not doing so may result in nasty bugs.

let palindrome = s === s.split('').reverse().join('')

You don't need this variable. It could've been:

if(s !== s.split('').reverse().join('')) {

Furthermore, if you wanted to declare a variable, it could've been a const here (you are not modifying it afterwards).

Just for fun, here's an alternative approach, using substrings from the original given string:

"hannach,ava,reopaper,annana,ewve,blob,otto,michael,racecaar,wasitacatiwsaw"
 .split(",")
 .forEach(name => console.log(`[${name}] => ${palindromeIndex(name)}`));
 
function palindromeIndex(s) {
 if (`${[...s]}` === `${[...s].reverse()}`) { return "is palindrome"; }
 let i = 0;
 while(i < s.length) {
 const sx = `${i < 1 ? s.substr(1, 0) : s.substr(0, i)}${s.substr(i + 1)}`; 
 const rsx = `${[...sx].reverse().join("")}`;
 if (sx === rsx) {
 return `removing '${s[i]}' (@ position ${i}): '${sx}'`;
 };
 i += 1;
 }
 return -1;
}

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