Problem 1:1000一下,能被3,5整除的数的和
If we list all the natural numbers below 10 that are multiples of 3 or 5,we get 3,5,6 and 9. The sum of these multiples is 23.
Find the sum of all the multiples of 3 or 5 below 1000.
my $sum=0; foreach(1..999) { $sum=$sum+$_ if(0==$_%3||0==$_%5); } print $sum."\n";
Problem 2,Fibonacci数列
Each new term in the Fibonacci sequence is generated by adding the prevIoUs two terms. By starting with 1 and 2,the first 10 terms will be:
1,2,3,8,13,21,55,89,...
By considering the terms in the Fibonacci sequence whose values do not exceed four million,find the sum of the even-valued terms.
use strict; use warnings; my $first_value =1; my $second_value=2; my $third_value =0; my $sum =2; while($third_value<4000000) { $third_value=$first_value+$second_value; if(0==$third_value%2) { $sum=$sum+$third_value; } $first_value =$second_value; $second_value=$third_value ; } print $sum;