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Solution in JavaScript warning: parseInt() is nutty!
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| function solution(X, Y, D) { | |
| let range = (Y - X); // max distance to go | |
| // special cases | |
| let hops = D === Y ? 0 : parseInt(range / D); // whole jumps [1] | |
| let extra = range % D; // any left over hops required | |
| console.log(`===>| X:${X} | Y:${Y} | D:${D} | range:${range} | hops:${hops} | extra:${extra} |`) | |
| return extra ? hops + 1 : hops | |
| } | |
| // [1] parseInt() [at least in Chrome] exhibits wonky behavior when working with small fractions. For example: | |
| // parseInt(1e-6) === 0 // true, but | |
| // parseInt(1e-7) === 0 // false | |
| // Why ? Because JavaScipt : https://stackoverflow.com/questions/27650459/function-parseint-1-10000000-returns-1-why | |
| // And the nature of JS numbers and the parsing functions inner workings | |
| // Therefore, the special case above make this function work on large number sets (e.g. | |
| // X= 99999999, Y= 1000000000, D = 1000000000 where D === Y | |
| // ===== Question | |
| /* | |
| https://app.codility.com/demo/results/trainingXMMT9P-S6D/ | |
| `Task description | |
| 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 | |
| Assume that: | |
| X, Y and D are integers within the range [1..1,000,000,000]; | |
| X ≤ Y. | |
| Complexity: | |
| expected worst-case time complexity is O(1); | |
| expected worst-case space complexity is O(1).` | |
| */ |
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