090-how-many-stairs-will-suzuki-climb-in-20-years.js

// Suzuki is a monk who climbs a large staircase to the monastery as part of a
// ritual. Some days he climbs more stairs than others depending on the number
// of students he must train in the morning. He is curious how many stairs
// might be climbed over the next 20 years and has spent a year marking down
// his daily progress.

// The sum of all the stairs logged in a year will be used for estimating the
// number he might climb in 20.

// 20_year_estimate = one_year_total * 20

// You will receive the following data structure representing the stairs
// Suzuki logged in a year. You will have all data for the entire year so
// regardless of how it is logged the problem should be simple to solve.

// stairs = [sunday,monday,tuesday,wednesday,thursday,friday,saturday] Make
// sure your solution takes into account all of the nesting within the stairs
// array.

// Each weekday in the stairs array is an array.

// sunday = [6737, 7244, 5776, 9826, 7057, 9247, 5842, 5484, 6543, 5153, 6832,
// 8274, 7148, 6152, 5940, 8040, 9174, 7555, 7682, 5252, 8793, 8837, 7320,
// 8478, 6063, 5751, 9716, 5085, 7315, 7859, 6628, 5425, 6331, 7097, 6249,
// 8381, 5936, 8496, 6934, 8347, 7036, 6421, 6510, 5821, 8602, 5312, 7836,
// 8032, 9871, 5990, 6309, 7825] Your function should return the 20 year
// estimate of the stairs climbed using the formula above.

function stairsIn20(s){
  return s.reduce((arr, day) => arr.concat(day)).reduce((acc, n) => acc + n) * 20;
}