{"id":41,"date":"2016-01-09T15:26:51","date_gmt":"2016-01-09T15:26:51","guid":{"rendered":"http:\/\/muthu.co\/?p=41"},"modified":"2021-01-02T14:06:16","modified_gmt":"2021-01-02T14:06:16","slug":"many-ways-of-writing-the-fibonacci-series-program-using-java","status":"publish","type":"post","link":"http:\/\/write.muthu.co\/many-ways-of-writing-the-fibonacci-series-program-using-java\/","title":{"rendered":"Many ways of writing the Fibonacci series program using Java"},"content":{"rendered":"

This is supposed to be a super simple program but how many ways can you write it?
\nHere are a few.<\/p>\n

Program 1 \u00a0– Fibonacci with 2 temp variables<\/strong><\/p>\n

public class Fibonacci {\r\n\u00a0 \u00a0 \u00a0 \u00a0 public static void main(String[] args) { \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 int n = 10;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 int f = 0, g = 1;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0for (int i = 1; i <= n; i++) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0f = f + g;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0g = f - g;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0System.out.println(f); \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n}<\/pre>\n
Program 2 – Fibonacci with 3 temp variables<\/strong><\/p>\n
public class Fibonacci { \r\n\u00a0 \u00a0 \u00a0 \u00a0 public static void main(String args[])\r\n\u00a0 \u00a0 \u00a0 \u00a0 { \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 int n = 10;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 int f1, f2=0, f3=1; \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 for(int i=1;i<=num;i++)\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 { \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0System.out.print(\" \"+f3+\" \"); \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0f1 = f2; \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0f2 = f3; \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0f3 = f1 + f2; \r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n}<\/pre>\n
Program 3 – Fibonacci using recursion<\/strong><\/p>\n
public class Fibonacci\r\n{\r\n\u00a0 \u00a0 \u00a0 \u00a0 public static void main(String[] args)\r\n\u00a0 \u00a0 \u00a0 \u00a0 {\u00a0\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 for(int i=0;i<10;i++)\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 System.out.println(fibonacci(i));\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 public static int fibonacci(int n) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 if(n == 0)\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return 0;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 else if(n == 1)\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return 1;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 else\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return fibonacci(n - 1) + fibonacci(n - 2);\r\n\u00a0 \u00a0 \u00a0 \u00a0 }\r\n}<\/pre>\n
 <\/p>\n
Program 4 – Fibonacci Using memorization<\/strong><\/p>\n
This method is used to improve the efficiency of our previous algorithms using Memoization<\/a>. We calculate only the missing values instead of calculating everything everytime.<\/p>\n
public class Fibonacci\r\n{\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/Cached object to store intermediate results of fibonacci series\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0private static Map<Integer,Integer> cache = null;\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0public static void main(String[] args)\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0{\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 cache = new HashMap<Integer, Integer>();\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 for(int i=0;i<10;i++){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0System.out.println(fibonacci(i));\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0public static int fibonacci(int n) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/First check if the value is available in the cache. If yes then take it out from there\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0if(cache.containsKey(n)){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return cache.get(n);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0int value = 0;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0if(n == 0){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 value = 0;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0else if(n == 1){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 value = 1;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 else{\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 value = fibonacci(n - 1) + fibonacci(n - 2);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \/\/Storing the value in cache\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 cache.put(n, value);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 return value;\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n}<\/pre>\n
  <\/p>\n","protected":false},"excerpt":{"rendered":"
This is supposed to be a super simple program but how many ways can you write it? Here are a few. Program 1 \u00a0– Fibonacci with 2 temp variables public class Fibonacci { \u00a0 \u00a0 \u00a0 \u00a0 public static void main(String[] args) { \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 int n = 10; \u00a0 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[51],"_links":{"self":[{"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/posts\/41"}],"collection":[{"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":1,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/posts\/41\/revisions"}],"predecessor-version":[{"id":1675,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/posts\/41\/revisions\/1675"}],"wp:attachment":[{"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/media?parent=41"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/categories?post=41"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/write.muthu.co\/wp-json\/wp\/v2\/tags?post=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}