Problem 1
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.
public int Counnt1(){int result = 0;int begin =3;int end = 1000;long t1 = System.currentTimeMillis();for(int i=begin; i<end; i++){if(i%3==0||i%5==0){result += i;}for_count1++;}long t2 = System.currentTimeMillis();System.out.println(t2-t1);return result ;}public int Counnt2(){int result = 0;int begin =3;int end = 1000;long t1 = System.currentTimeMillis();for(int i=begin; i<end; i=i+3){result += i;for_count2++;}for(int i=5;i<end;i=i+5){result += i;for_count2++;}for(int i=15; i<end; i=i+15){result -=i;for_count2++;}long t2 = System.currentTimeMillis();System.out.println(t2-t1);return result;}