TL;DR: The fastest algorithm looks at every element once, keeping track of the largest one seen so far. Details. Intuition tells us that any correct algorithm must look at every element in the array, that's why we can't do better. Let's find an actual proof.
Drugs are addictive  because they either mimic or stimulate the production of brain chemicals that cause feelings of pleasure. After a period of time, your brain adjusts to the higher levels of the chemicals, and it becomes necessary to use more drugs to get the same effect.
Only about 9% will have a serious addiction. For an excellent post on the biology of marijuana addiction see http://www.psychologytoday.com/blog/all-about-addiction/201001/is-marijuana-addictive-you-can-bet-your-heroin. The large majority of people who try marijuana do it experimentally and never become addicted.ocaine and heroin are more physically harmful and nicotine is much more addictive. It is much harder to quit smoking cigarettes than it is to quit smoking pot. Recreational users of the past are often compared to todays smokers. The smokers, the times and the pot are all different.