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Next Greater elements in left

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Greater elements in left using stack


function next_greater_left(arr)
{
  var v = [];
  var s = [];
  for(var i = 0; i < arr.length; i++)
  {
    if(s.length == 0)
    {
      v.push(-1);
    }
    else if(s.length > 0 && s[s.length - 1] > arr[i])
    {
      v.push(s[s.length - 1]);
    }
    else if(s.length > 0 && s[s.length - 1] <= arr[i])
    {
      while(s.length > 0 && s[s.length - 1] <= arr[i])
      {
        s.pop();
      }
      if(s.length == 0)
      {
        v.push(-1);
      }
      else
      {
        v.push(s[s.length - 1]);
      }
    }
    s.push(arr[i]);
  }
  return v;
}