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package com.dvp.tutoriel.fibonacci; |
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import java.util.HashMap; |
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import java.util.Map; |
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6 | 12 | public class MaCalculette implements Calculette { |
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8 | 1 | private static Map<Integer, Long> map = new HashMap<Integer, Long>(); |
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private final static double NOMBRE_OR = 1.61803398874989; |
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private final static double RACINE_5 = 2.236067977499; |
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public Long fibonacciAvecNombreOr(Integer n) { |
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15 | 0 | if (n <= 0) { |
16 | 0 | throw new IllegalArgumentException("On ne calcule que pour des nombres positifs"); |
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} |
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21 | 0 | if (n == 1 || n == 2) { |
22 | 0 | return 1L; |
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} |
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25 | 0 | final double nominateur = Math.pow(NOMBRE_OR, n); |
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27 | 0 | final double result = nominateur / RACINE_5; |
28 | 0 | return Math.round(result); |
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} |
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@Override |
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public Long fibonacci(Integer n) { |
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35 | 118 | if (n <= 0) { |
36 | 2 | throw new IllegalArgumentException("On ne calcule que pour des nombres positifs"); |
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} |
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41 | 116 | if (n == 1 || n == 2) { |
42 | 5 | return 1L; |
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} |
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47 | 111 | Long valeur = map.get(n); |
48 | 111 | if (valeur != null) { |
49 | 58 | return valeur; |
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} |
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53 | 53 | valeur = fibonacci(n - 1) + fibonacci(n - 2); |
54 | 53 | map.put(n, valeur); |
55 | 53 | return valeur; |
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} |
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} |