sum of multiples - Printable Version

sum of multiples - Printable Version

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+--- Thread: sum of multiples (/Thread-sum-of-multiples)

sum of multiples - blackeagle - 09-22-2014

Find the sum of the multiples of 5 or 7 under 851

i know it's easy but i didn't sleep well yesterday and i'm eally not focued can't figure out what im doing wrong here here's my code help appreciated pls !!

Spoiler:Code:
public static void main(String[] args) {
        int sum1 = 0, sum2 = 0;
        int i = 0;
        int i1 = 0;
        do {
            i = i + 5;
        } while (i < 851);

        System.out.println(i);

        do {
            i1 = i1 + 7;
        } while (i1 < 851);

        System.out.println(i1);
        i += i1;
        System.out.println("solution = " + i);
    }
}

Spoiler:Code:
public static void main(String[] args) {
        int sum1 = 0, sum2 = 0;
        int i = 0;
        int i1 = 0;
        do {
            i = i + 5;
        } while (i < 851);

        System.out.println(i);

        do {
            i1 = i1 + 7;
        } while (i1 < 851);

        System.out.println(i1);
        i += i1;
        System.out.println("solution = " + i);
    }
}

RE: sum of multiples - dropzon3 - 09-22-2014

You're not tracking the sum anywhere? You are looking over the multiples of 5 and 7 with the i += 5 and i +=7 but the sum isn't being stored. You should do something like

Code:
do {
    i = i + 5;
    sum += i //add i to sum
} while (i < 851);

similar code for the multiples of 7

Code:
do {
    i = i + 5;
    sum += i //add i to sum
} while (i < 851);

similar code for the multiples of 7

RE: sum of multiples - blackeagle - 09-22-2014

omg i feel like an idiot now :/ thx for the help @dropzon3