some one can help me , to solve this recursion , the question we must arrange the letter , if next letter not the sequence,it must be our output
function dataReducer(data) {
}
console.log(dataReducer('abcdxefgh5wi')); // 'x,5,w'
console.log(dataReducer('opqrstu')); // ''
console.log(dataReducer('acdefghij')); // 'c,d,e,f,g,h,i,j'
console.log(dataReducer('testu')); // 'e,s,t'
and totally redeem yourself !
SO likes to punish people if they don't show their work, but I'm not one to judge. I do think you will learn more if you try these problems on your own, but I know what it's like to be completely bewildered; and no good-natured soul amongst us wants to see you get stuck.
With that in mind, I really do think you can learn a lot from this answer. Please study it carefully and ask follow-up questions if you're confused.
const ord = c =>
c.charCodeAt (0)
const isCharSeq = (x, y) =>
ord (x) + 1 === ord (y)
const dataReducer = ([x, ...xs], last = null, acc = []) =>
x === undefined
? acc.join (',')
: last === null
? dataReducer (xs, x, acc)
: isCharSeq (last, x)
? dataReducer (xs, x, acc)
: dataReducer (xs, last, acc.concat ([x]))
console.log (dataReducer ('abcdxefgh5wi')) // 'x,5,w'
console.log (dataReducer ('opqrstu')) // ''
console.log (dataReducer ('acdefghij')) // 'c,d,e,f,g,h,i,j'
console.log (dataReducer ('testu')) // 'e,s,t'
console.log (dataReducer ('a')) // ''
console.log (dataReducer ('')) // ''
dataReducer is implemented with a proper tail call which means it can be optimised and even work on strings that are millions or billions of characters in length – even if JavaScript VM's never support this optimisation, don't worry, you can DIY.
