Any reliable source of info or website to get accurate numbers of outstanding shares of comapnies?

What source can I use it to get the "exact" number of outstanding shares up to date? Because I'm trying to do extensive research regarding this and looked up Microsoft's number of outstanding shares and EVERY WEBSITE showed slightly different numbers and it's driving crazy.

Also I feel like average retail investors get screwed over when a company issues a large number of additional shares without any warning and get their shares diluted. So even if the investor made a "correct" investment, the shares they own can still go down if the company decides to just dilute the shares. Is there any reason how that's legal?