根据牛津高级英语学习词典，楼主问的肯定是两者意思一样的区别。两者都有“突然想到”的意思。
1）come to somebody[no passive] (of an idea) to enter your mind
The idea came to me in the bath.
It suddenly came to her that she had been wrong all along.
2）occur to somebody(of an idea or a thought)
to come into your mind
The idea occurred to him in a dream.
It didn't occur to him that his wife was having an affair.
It didn't occur to her to ask for help.
3）异同点
a: come to sb 和 occur to sb在想到一个主意的时候，是可以互换的。
b: 两者均可以接that从句
c: occur to sb后面可以接动词不定式。但come to sb后面不可以接。