Recursion — Factorial

Fundamentals/Recursion — FactorialO(n)— O(n) — call stack grows with input size

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Code Editor— O(n) — call stack grows with input size

read-onlyJavaScript

// Factorial — recursion's call stack made visible.
// Descent pushes a frame per call; unwind multiplies back up.
let n = 6;
let stack = [];

// Descent: fact(6) → fact(5) → ... → fact(2)
for (let i = n; i > 1; i--) {
  stack.push(i);
}

// Unwind: multiply each frame back into the result
let result = 1;
while (stack.length > 0) {
  let frame = stack.pop();
  result = result * frame;
}

let ans = result;
// ans = 720  (6! = 720)

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