06_Almost Increasing Sequence.js

// Difficulty: Medium

// Given a sequence of integers as an array, determine whether it is possible to obtain a strictly increasing sequence by removing no more than one element from the array.

// Note: sequence a0, a1, ..., an is considered to be a strictly increasing if a0 < a1 < ... < an. Sequence containing only one element is also considered to be strictly increasing.

// Resolve:

function almostIncreasingSequence(sequence) {
  let count = 0;
  for (let i = 0; i < sequence.length; i++) {
    if (sequence[i] <= sequence[i - 1]) {
      count++;
      if (
        sequence[i] <= sequence[i - 2] &&
        sequence[i + 1] <= sequence[i - 1]
      ) {
        return false;
      }
    }
  }
  return count <= 1;
}

console.log(almostIncreasingSequence([1, 3, 2, 1]));