Umbrella Challenge

A-umbrella.md

Umbrella Challenge

Given a number of people N and an array of integers, each one representing the amount of people a type of umbrella can handle, output the minimum number of umbrellas needed to handle N people.

No umbrella could have left spaces. Which means if a umbrella can handle 2 people, there should be 2 people under it.

If there's no solution, return -1.

Examples

solve(3, [1, 2]) means that we have 3 people and two kinds of umbrellas, one that hanled one person and one that handles 2. We can give one two-sized umbrella to 2 of them and the other to the last person. Therefore the solution is 2 (umbrellas). You could give 3 one-sized umbrellas, but we want the minimum number.

solve(10, [3, 1]). You can give 3 three-sized umbrellas and 1 one-sized. This means the solution is 4.

solve(3, [2]). There's no solution since one umbrella would have empty space. Return -1.

B-umbrella.js

function solve(n, umbrellas) {
  return -1
}

const tests =
[ { n: 3
  , umbrellas: [1, 2]
  , expect: 2
  }
  
, { n: 10
  , umbrellas: [3, 1]
  , expect: 4
  }

, { n: 3
  , umbrellas: [2]
  , expect: -1
  }
]

tests.forEach(({n, umbrellas, expect}) =>
  console.log(`solve(${n}, [${umbrellas}])`)        ||
  console.log(`   Expects: ${expect}`)              ||
  console.log(`   Output:  ${solve(n, umbrellas)}`) ||
  console.log()
)