Distribution calculation method for the Peak game

peaks.js

(()=>{
  const distribution = [8,12,20,12,10,20,17,1];
console.log(distribution.reduce((x,y)=>x+y, 0));
return (distribution.reduce(function (array, cur){
  const previous = array[array.length-1]|| []
    , previousRemoved = previous[0]||0
    , previousRemaining = previous[1]||100;
  return array.concat([[cur, previousRemaining - previousRemoved]]);
}, []).map((x)=>x.join("/")).join(', '));
})();
/*
 8/100, 12/92, 20/80, 12/60, 10/48, 20/38, 17/18
 2/25,   3/23,  1/4 ,  2/10,  5/24, 10/19, 17/18
 2d13,  2d12,  1d4,   1d10,  1d24,  2d10,  1d18
 3<,    5<,   1<,     2<,    5<,   11<,   =18
 */