Bugl — code interview practice that feels like a game

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Flash cards

Review the key moves

1/4

Core idea

What is the main idea behind Java How To Find the GCD?

Lesson checks

Practice each idea before moving on

Short Mimo-style checks built from this lesson's code, terms, and sequence.

1Quick choice

Which statement best captures the main point of this lesson?

2Fill blank

Complete the missing token from the example code.

___ gcd = 1;

3Order

Put the learning moves in the order that makes the concept easiest to apply.

We want the largest number that divides both 36 and 60 without a remainder.

The GCD (Greatest Common Divisor) is the largest number that divides two numbers without leaving a remainder.

Find the Greatest Common Divisor (GCD)

The GCD (Greatest Common Divisor) is the largest number that divides two numbers without leaving a remainder.

Example

int a = 36;
int b = 60;
int gcd = 1;
for (int i = 1; i <= a && i <= b; i++) {
  if (a % i == 0 && b % i == 0) {
    gcd = i;
  }
}
System.out.println("GCD: " + gcd);

Explanation

We want the largest number that divides both 36 and 60 without a remainder.

The loop starts at 1 and goes up to the smaller number (36).
At each step, we check if i divides both numbers (using % , the remainder operator).
If it does, we update gcd to that value.

For example

36 % 12 == 0 and 60 % 12 == 0 , so 12 is a divisor of both.
Later, the loop finds gcd = 12 as the largest common divisor.

So the program prints GCD: 12 .