Counting Valleys - Javascript

counting-valleys.js

// Complete the countingValleys function below.
function countingValleys(n, s) {
  let level = 0;
  let numberOfValleys = 0;

  for (let i = 0; i < n; i++) {
    const next = s[i]
    if (next === 'U') {
      if (level === -1) {
        numberOfValleys = numberOfValleys + 1;
      }
      level = level + 1;
    } else if (next === 'D') {
      level = level - 1;
    }
  }
  return numberOfValleys;
}