A 40-year-old hypeensive lady is brought to the emergency room after being unresponsive following a sudden bout of severe headache, vomiting and neck rigidity at work. 0/E her BP is 180/100 mmHg and her respiration is irregular and of Cheyne-Stokes type. She is agitated and doesn't follow commands, but moves her extremities spontaneously. Most likely diagnosis will be: JIPMER 08; AIIMS 13