mumbling.ts

function accum(s:string){
  return s.split('').map((letter, idx)=>{
      let output = letter.repeat(idx + 1).toLowerCase();
   return capitalizeFirstLetter(output);
  }).join('-')
}

function capitalizeFirstLetter(string : string) {
  return string.charAt(0).toUpperCase() + string.slice(1);
}

// and my favorite solution from another warrior
function accumtwo(s : string) {
  return s.split('').map((c, i) => (c.toUpperCase() + c.toLowerCase().repeat(i))).join('-');
}