perlmeditation darkblackblue <p>Hi My goal is read only line from file , and find fibonacci series that has minimun 3 element.I want to control numbers from 1 to 6 digit. Fibonacci series starts 1,1,2,3,5,8,13,21,34,55,89, ...... .For example;File text document </p> <p>49693463452312343388645</p> <p>I division string 1 to 6 digit. Check 4 is fibonacci number , no , go ahaed 49 is fibonacci number , no, next 496 is fibonacci ,no, 4969 after 44693 ,after 496934 no.There isnt any fibonacci , go to next digit and do it again 9 , 96,969,9693,96934. </p> <code> use 5.010; use strict; use warnings; open(FILE, "<:encoding(UTF-8)", "aa.txt") or die "Could not open file: \$!"; my \$numbers; while (<FILE>) { \$numbers="\$_" ; print "\$_"; } chomp \$numbers; print "\n\$numbers"; my \$len=length(\$numbers); print "\n\$len\n"; my \$i; my \$abc; foreach my \$i (0..\$len){ foreach my \$j (1..6) { print "\$j----->"; \$abc = substr(\$numbers,\$i,\$j); print "\$abc\n"; } print "***********************************\n"; } close FILE; </code> <p>I read to find fibonacci series with PERFECT SQUARE. I didn't use it. C code example </p> <code> // C++ program to check if x is a perfect square #include <iostream> #include <math.h> using namespace std; // A utility function that returns true if x is perfect square bool isPerfectSquare(int x) { int s = sqrt(x); return (s*s == x); } // Returns true if n is a Fibinacci Number, else false bool isFibonacci(int n) { // n is Fibinacci if one of 5*n*n + 4 or 5*n*n - 4 or both // is a perferct square return isPerfectSquare(5*n*n + 4) || isPerfectSquare(5*n*n - 4); } // A utility function to test above functions int main() { for (int i = 1; i <= 10; i++) isFibonacci(i)? cout << i << " is a Fibonacci Number \n": cout << i << " is a not Fibonacci Number \n" ; return 0; } </code> <p><small><i>2017-12-29 [Athanasius] restored original content</small></p>