 오늘의 기억

# [Algorithm] FrogJmp

## Question

A small frog wants to get to the other side of the road. The frog is currently located at position X and wants to get to a position greater than or equal to Y. The small frog always jumps a fixed distance, D.

Count the minimal number of jumps that the small frog must perform to reach its target.

Write a function:

``````function solution(X, Y, D);
``````

that, given three integers X, Y and D, returns the minimal number of jumps from position X to a position equal to or greater than Y.

For example, given:

``````  X = 10
Y = 85
D = 30
``````

the function should return 3, because the frog will be positioned as follows:

• after the first jump, at position 10 + 30 = 40
• after the second jump, at position 10 + 30 + 30 = 70
• after the third jump, at position 10 + 30 + 30 + 30 = 100

Write an efficient algorithm for the following assumptions:

• X, Y and D are integers within the range [1..1,000,000,000];
• X ≤ Y.

## Solution (TypeScript)

``````function solution(x: number, y: number, d: number) {
if (x === y) {
return 0;
}
return Math.ceil((y - x) / d);
}
``````

Author: Codility, Lesson 3

20200106 Charyum.Park