C++ newbie here and I have run into an issue which I can't figure out.
When I run the code below I get the correct results I expected:
#include <iostream>
#include <math.h>
void factorize(int *factors, int number)
{
// declare vars
int index = 0;
// find factors of number
for (int x = 1; x <= number; ++x) {
// if x is a factor of number, save it to array
if (number % x == 0) {
std::cout << " Index: " << index << ", F: " << x << "\n";
index++;
}
}
}
int main()
{
//declare vars
int triangle = 0;
int factors[] = {};
//loop through all numbers
for (int x = 1; x <= 5; ++x) {
// calculate triangle value
std::cout << "initial triangle value: " << triangle << ", ";
triangle = triangle + x;
std::cout << "x value: " << x << " , new triangle value: " << triangle << "\n\n";
// find factors of triangle number
factorize(factors, triangle);
std::cout<<"\n";
}
return 0;
}
Correct results:
initial triangle value: 0, x value: 1 , new triangle value: 1
Index: 0, F: 1
initial triangle value: 1, x value: 2 , new triangle value: 3
Index: 0, F: 1
Index: 1, F: 3
initial triangle value: 3, x value: 3 , new triangle value: 6
Index: 0, F: 1
Index: 1, F: 2
Index: 2, F: 3
Index: 3, F: 6
initial triangle value: 6, x value: 4 , new triangle value: 10
Index: 0, F: 1
Index: 1, F: 2
Index: 2, F: 5
Index: 3, F: 10
initial triangle value: 10, x value: 5 , new triangle value: 15
Index: 0, F: 1
Index: 1, F: 3
Index: 2, F: 5
Index: 3, F: 15
But when I add the line factors[index] = x; to the factorize function, I get strange results. For some reason, the value of triangle in main is modified.
#include <iostream>
#include <math.h>
void factorize(int *factors, int number)
{
// declare vars
int index = 0;
// find factors of number
for (int x = 1; x <= number; ++x) {
// if x is a factor of number, save it to array
if (number % x == 0) {
std::cout << " Index: " << index << ", F: " << x << "\n";
factors[index] = x;
index++;
}
}
}
int main()
{
//declare vars
int triangle = 0;
int factors[] = {};
//loop through all numbers
for (int x = 1; x <= 5; ++x) {
// calculate triangle value
std::cout << "initial triangle value: " << triangle << ", ";
triangle = triangle + x;
std::cout << "x value: " << x << " , new triangle value: " << triangle << "\n\n";
// find factors of triangle number
factorize(factors, triangle);
std::cout<<"\n";
}
return 0;
}
Unexpected results (notice how the triangle value goes: 0, 1, 3, but then for some reason jumps back to 2):
initial triangle value: 0, x value: 1 , new triangle value: 1
Index: 0, F: 1
initial triangle value: 1, x value: 2 , new triangle value: 3
Index: 0, F: 1
Index: 1, F: 3
initial triangle value: 3, x value: 3 , new triangle value: 6
Index: 0, F: 1
Index: 1, F: 2
Index: 2, F: 3
Index: 3, F: 6
initial triangle value: 2, x value: 4 , new triangle value: 6
Index: 0, F: 1
Index: 1, F: 2
Index: 2, F: 3
Index: 3, F: 6
initial triangle value: 2, x value: 5 , new triangle value: 7
Index: 0, F: 1
Index: 1, F: 7
What am I missing?
