Today,i write a medium program for me.It come about a surprising result that i can't image .It should come about 82 errors which make me don't trust the compiler.After all ,the compiler is righte.So i have to solve it one by one .At last,i almost spend a two hours to solve  all problems.It's lucky to get the executables.I have to say that It's a bad day,but i realize that the many basic knows is fading away from my mind .I should reiew it.