USING A LOOP, multiply all of the numbers between 3 and 8

Question

I'm not totally sure where to start with this program. I was just introduced to loops and have done a couple simple loops. This question doesn't make sense to me. Basically it is supposed to read

answer is 3
answer is 12
answer is 60
answer is 360
answer is 2520
answer is 20160

I can make it read this but only by hard coding... Do I use while statements? if statements? else statements? I am so lost and have been trying for about an hour already.

Show what you've tried, and tell us what problem you encountered. — songyuanyao, Feb 22 '16 at 07:36
it's pretty hard to say anything about this without just giving the answer ... — M.M, Feb 22 '16 at 08:08

Codor · Answer 1 · 2016-02-22T07:52:09.577

4

The problem could be solved with one for loop as follows.

int Product = 1;

for (int i = 3; i <= 8; i++)
{
    Product = Product * i;
    // if desired, do something useful with Product
}

edited Feb 22 '16 at 07:52

answered Feb 22 '16 at 07:42

Codor

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This doesn't match the required output. It's actually much easier to do with a single loop multiplying onto some variable – swinefish Feb 22 '16 at 07:47
1

Yes, I somewhat misunderstood question. The desired outcome in total would be 3 * 4 * 5 * 6 * 7 * 8, not some pairwise products. – Codor Feb 22 '16 at 09:14
@Codor Me too..I didn't read the question well. I thought it was to print the pattern infinitely.. My bad. – Nidhin David Feb 22 '16 at 09:17

score 0 · Answer 2 · edited Feb 22 '16 at 09:35

0

This follows a pattern

3*4 = 12
(3*4)*5 = 12 * 5 = 60
(3*4*5)*6 = 60 * 6 = 360
(3*4*5*6)*7 = 360 * 7 = 2520
(3*4*5*6*7)*8 = 2520 * 8 = 20160

code in C++

     int result = 1;
     for(int i =3; i<=8;i++)
     {
         result = result * i;
         cout<<"answer is"<<result;
     }

edited Feb 22 '16 at 09:35

Skywalker

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answered Feb 22 '16 at 08:17

Nidhin David

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`for(counter = 4 ; counter>0; counter++)` certainly doesn't look right. – dasdingonesin Feb 22 '16 at 08:31
@dasdingonesin It works. I tried it in JS. Please remove the down vote if you did it. – Nidhin David Feb 22 '16 at 08:35
1. The question is about C++, not JavaScript. 2. The question asks how to multiply the numbers from 3 to 8, not from 3 to signed integer overflow, i.e. undefined behaviour. – dasdingonesin Feb 22 '16 at 08:38
@dasdingonesin Its for infinite loop – Nidhin David Feb 22 '16 at 08:40
[No, it isn't.](http://stackoverflow.com/questions/16188263/is-signed-integer-overflow-still-undefined-behavior-in-c) Also, why would you want an infinite loop? – dasdingonesin Feb 22 '16 at 08:43
@dasdingonesin I didn't notice upto 8 condition. – Nidhin David Feb 22 '16 at 08:46
Eh, `for (var counter = 4; counter > 200000; counter++)`? The body of that loop will not be executed a single time. – Sebastian Mach Feb 22 '16 at 08:51
@dasdingonesin Now its working...Please verify it and remove the downvote – Nidhin David Feb 22 '16 at 08:58
@phresnel I corrected the code. I was only constructing it. sory or the stupid mistake please verify it now – Nidhin David Feb 22 '16 at 08:59
@rozina Please see the 2nd edits of my answer....run this code int accumulator = 3; for(counter = 4 ; counter>0; counter++) { printf("Answer is %d \n", counter); accumulator = accumulator * counter; } – Nidhin David Feb 22 '16 at 09:05

score 0 · Answer 3 · answered Feb 22 '16 at 08:42

0

int out = 1;
for (int i = 3; i < 9; ++i)
{
    out *= i;
    cout << out << endl;
}

answered Feb 22 '16 at 08:42

Dave Chandler

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USING A LOOP, multiply all of the numbers between 3 and 8

3 Answers3