README

Simple Fun #74: Growing Plant

Task

Each day a plant is growing by upSpeed meters. Each night that plant’s height decreases by downSpeed meters due to the lack of sun heat. Initially, plant is 0 meters tall. We plant the seed at the beginning of a day. We want to know when the height of the plant will reach a certain level.

Example

For upSpeed = 100, downSpeed = 10 and desiredHeight = 910, the output should be 10.

 After day 1 --> 100
 After night 1 --> 90
 After day 2 --> 190
 After night 2 --> 180
 After day 3 --> 280
 After night 3 --> 270
 After day 4 --> 370
 After night 4 --> 360
 After day 5 --> 460
 After night 5 --> 450
 After day 6 --> 550
 After night 6 --> 540
 After day 7 --> 640
 After night 7 --> 630
 After day 8 --> 730
 After night 8 --> 720
 After day 9 --> 820
 After night 9 --> 810
 After day 10 --> 910

For upSpeed = 10, downSpeed = 9 and desiredHeight = 4, the output should be 1.

Because the plant reach to the desired height at day 1(10 meters).

After day 1 --> 10

Input/Output

• input integer upSpeed

  A positive integer representing the daily growth.

  Constraints: 5 ≤ upSpeed ≤ 100.

• input integer downSpeed

  A positive integer representing the nightly decline.

  Constraints: 2 ≤ downSpeed < upSpeed.

• input integer desiredHeight

  A positive integer representing the threshold.

  Constraints: 4 ≤ desiredHeight ≤ 1000.

• output an integer

The number of days that it will take for the plant to reach/pass desiredHeight (including the last day in the total count).

Source