linear.js

// O(n)
function linear1(n) {
  for (let i = 1; i <= n; i++) {
    console.log(i);
  }
}

// O(n), where n is the length of the array
function linear2(array) {
  for (let i = 0; i < array.length; i++) {
    console.log(i);
  }
}

// O(n)
function linear3(n) {
  if (n === 1) return;
  linear3(n - 1);
}