https://www.youtube.com/watch?v=ZfKTD5lvToE
about "perfect" numbers. I was thinking that nobody really sits around trying to calculate these things do they?
Anyway I thought it might be cool to practice my arduino programming skills to replicate the results. It took about 4 hours but I learned a lot about how to manipulate arrays. Here are the results:
and here's the code I came up with:
unsigned int number = 2; //the number being tested
unsigned int divisor = 1; //divisor to find factors
int r = 0; //remainder
int f = 0; //test factor
int fCount = 0; //interger for storing array values
int factors[32]; //array to store the factors
int sum = 0; //sum of factor interger
int lim = 10000; //highest number to check
int i = 0;
void setup() {
Serial.begin(9600);
}
void loop() {
while(number < lim){
//Serial.print("number:");
//Serial.print("\t");
//Serial.println(number);
//Serial.print("factors:");
//Serial.print("\t");
while(divisor <= number){
r = number % divisor;
f = number / divisor;
if(r == 0){
factors[fCount] = f;
fCount++;
}
divisor++;
}
for(i = 0; i < fCount; i = i + 1){
//Serial.print(factors[i]);
//Serial.print("\t");
}
//Serial.println();
for(i = 1; i <fCount; i = i + 1){
sum = sum + factors[i];
}
//Serial.print("sum:");
//Serial.print("\t");
//Serial.println(sum);
if(sum == number){
Serial.print("Found one!");
Serial.print("\t");
Serial.println(number);
Serial.print("The factors are:");
Serial.print("\t");
for(i = 1; i < fCount; i = i + 1){
Serial.print(factors[i]);
Serial.print("\t");
}
Serial.println();
Serial.print("Found at:");
Serial.print("\t");
Serial.print(millis());
Serial.println(" milliseconds");
Serial.println();
}
//Serial.println();
sum = 0;
fCount = 0;
divisor = 1;
number = number + 2;
}
if(number == lim){
Serial.println("Done!");
delay(60000);
}
}
It could probably be optimized a lot more. I told the program to ignore odd numbers to speed it up but I'm sure it could use it's information to ignore more numbers by the looks of it. There's a bunch of commented out lines for debugging but it works. It was more of a learning tool for me than anything. Arrays are no-longer a mystery!
