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+---- Thread: [C] Need to create a simple program for homework (/showthread.php?tid=5902303)
Need to create a simple program for homework - Voxi - Nov 1, 2018
Here is what I have to do:
You know that the combination to a safe is a four-digit integer (between 1000 and 9999) that:
a) is a perfect square, and
b) is not divisible by 2, 3 or 5.
Could anyone help me out on where i'd start? I'm really bad at C++ and think i'm gonna fail my class lol
RE: Need to create a simple program for homework - Mouse❤️ - Nov 1, 2018
If that's your assignment, I see why you're failing. There aren't even any instructions. It's just telling you what an incorrect definition of a number combination is.
RE: Need to create a simple program for homework - Souffrance - Nov 1, 2018
Assuming you have to code it, the way I would start is by having a loop that goes from:
32 till 99.
In each of these iterations of the loop, get the squared number (i.e. number times itself, then check if it's divisible by 2, 3 or 5.) If it isn't divisible by any of them. Print it out.
Of course that's just assuming this is what the assignment actually wants you to do.
You'll need to use a for loop and an if statement to accomplish this.
RE: Need to create a simple program for homework - int main() - Nov 2, 2018
(Nov 1, 2018 03:55 PM)Mouse❤️ Wrote: If that's your assignment, I see why you're failing. There aren't even any instructions. It's just telling you what an incorrect definition of a number combination is.
LOOOOOOOOOL poor guy
RE: Need to create a simple program for homework - FoxBlood - Nov 2, 2018
Nobody will help you here, it's about your programming education, if you don't like programming that means you are in a wrong school
RE: Need to create a simple program for homework - Abruptum - Nov 2, 2018
Hey,
The Solution is quite easy to understand.
Code
#include <math.h>
#include <iostream>
using namespace std;
bool isDivisible(int x, int n);
bool isPerfectSquare(int n);
int main(){
int a=1000;
while(a<10000){
if(!isDivisible(a,2) && !isDivisible(a,3) && !isDivisible(a,5) && isPerfectSquare(a)){
cout<<a<<"\n";
}
a++;
}
return 0;
}
bool isPerfectSquare(int n){
int squareRootN=(int)(sqrt((double)n)+0.5);
return squareRootN*squareRootN == n;
}
bool isDivisible(int x, int n){
return ((double)x/(double)n) == (double)(x/n);
}Do it now yourself, use stackoverflow and other sites to gain informations how other people have solved this problem.
(There is a better version and you should be able to create it now on your own)
RE: Need to create a simple program for homework - Souffrance - Nov 2, 2018
(Nov 2, 2018 08:37 AM)Abruptum Wrote: Hey,
The Solution is quite easy to understand.
Code#include <math.h>
#include <iostream>
using namespace std;
bool isDivisible(int x, int n);
bool isPerfectSquare(int n);
int main(){
int a=1000;
while(a<10000){
if(!isDivisible(a,2) && !isDivisible(a,3) && !isDivisible(a,5) && isPerfectSquare(a)){
cout<<a<<"\n";
}
a++;
}
return 0;
}
bool isPerfectSquare(int n){
int squareRootN=(int)(sqrt((double)n)+0.5);
return squareRootN*squareRootN == n;
}
bool isDivisible(int x, int n){
return ((double)x/(double)n) == (double)(x/n);
}
Do it now yourself, use stackoverflow and other sites to gain informations how other people have solved this problem.
(There is a better version and you should be able to create it now on your own)
This is inefficient, I'm not sure why you're checking if each number is a perfect square at all. Just generate only perfect squares instead.
RE: Need to create a simple program for homework - icko1996 - Nov 2, 2018
Don't forget about the modulus operator.
You can check if a number is divisible by another number the following way:
( x % y ) == 0, where x is the dividend, y the divisor.
Good luck with your assignment!
RE: Need to create a simple program for homework - Abruptum - Nov 2, 2018
(Nov 2, 2018 12:21 PM)Souffrance Wrote: This is inefficient, I'm not sure why you're checking if each number is a perfect square at all. Just generate only perfect squares instead.
OMG ;D it was just an bad example so he could improve it.
Pleas read the whole post and don't bitch around.
RE: Need to create a simple program for homework - incognito04 - Nov 14, 2018
A short example program 🤝.
PHP Code
<?php
#include <cmath>
#include <array>
#include <vector>
#include <iostream>
#include <numeric>
#include <algorithm>
int main()
{
const auto is_div = [](const short x, const short y) -> bool {
return x % y == 0;
};
const auto is_sqrt = [](const short n) -> bool {
const auto sr = std::sqrt(n);
return ((sr - std::floor(sr)) == 0);
};
std::array<short, 9000> data;
std::iota(data.begin(), data.end(), 1000);
std::vector<short> copyOfData;
const auto itr = std::copy_if(data.begin(), data.end(), std::back_inserter(copyOfData), [&is_div, &is_sqrt](const short n) {
return is_sqrt(n) && is_div(n, 2) && is_div(n, 3) && is_div(n, 5);
});
for (const auto n : copyOfData)
std::cout << n << '\n';
return 0;
}
RE: Need to create a simple program for homework - kray - Nov 15, 2018
(Nov 1, 2018 03:55 PM)Mouse❤️ Wrote: If that's your assignment, I see why you're failing. There aren't even any instructions. It's just telling you what an incorrect definition of a number combination is.
after first reading the original post, I was confused. After reading your reply, I laughed so hard I'm now dead.