filter useless snippets when add a problem and rustfmt code

[whalecold]

filter useless tag like this:

* Input: 
 * 
 * 1 0 1 0 0
 * 1 0 <font color="red">1 <font color="red">1 1
 * 1 1 <font color="red">1 <font color="red">1 1
 * 1 0 0 1 0
 * 
 * Output: 4
 * 
 */

[whalecold]

I format the two rust file with rustfmt

[aylei]

Sorry for the late response, the patch looks good to me! could you please resolve the merge conflicts?