B. Curiosity Has No Limits
When Masha came to math classes today, she saw two integer sequences of length n−1n−1 on the blackboard. Let's denote the elements of the first sequence as aiai (0≤ai≤30≤ai≤3), and the elements of the second sequence as bibi (0≤bi≤30≤bi≤3).
Masha became interested if or not there is an integer sequence of length nn, which elements we will denote as titi (0≤ti≤30≤ti≤3), so that for every ii (1≤i≤n−11≤i≤n−1) the following is true:
- ai=ti|ti+1ai=ti|ti+1 (where || denotes the ) and
- bi=ti&ti+1bi=ti&ti+1 (where && denotes the ).
The question appeared to be too difficult for Masha, so now she asked you to check whether such a sequence titi of length nn exists. If it exists, find such a sequence. If there are multiple such sequences, find any of them.
The first line contains a single integer nn (2≤n≤1052≤n≤105) — the length of the sequence titi.
The second line contains n−1n−1 integers a1,a2,…,an−1a1,a2,…,an−1 (0≤ai≤30≤ai≤3) — the first sequence on the blackboard.
The third line contains n−1n−1 integers b1,b2,…,bn−1b1,b2,…,bn−1 (0≤bi≤30≤bi≤3) — the second sequence on the blackboard.
In the first line print "YES" (without quotes), if there is a sequence titi that satisfies the conditions from the statements, and "NO" (without quotes), if there is no such sequence.
If there is such a sequence, on the second line print nn integers t1,t2,…,tnt1,t2,…,tn (0≤ti≤30≤ti≤3) — the sequence that satisfies the statements conditions.
If there are multiple answers, print any of them.
4 3 3 2 1 2 0
YES 1 3 2 0
3 1 3 3 2
NO
In the first example it's easy to see that the sequence from output satisfies the given conditions:
- t1|t2=(012)|(112)=(112)=3=a1t1|t2=(012)|(112)=(112)=3=a1 and t1&t2=(012)&(112)=(012)=1=b1t1&t2=(012)&(112)=(012)=1=b1;
- t2|t3=(112)|(102)=(112)=3=a2t2|t3=(112)|(102)=(112)=3=a2 and t2&t3=(112)&(102)=(102)=2=b2t2&t3=(112)&(102)=(102)=2=b2;
- t3|t4=(102)|(002)=(102)=2=a3t3|t4=(102)|(002)=(102)=2=a3 and t3&t4=(102)&(002)=(002)=0=b3t3&t4=(102)&(002)=(002)=0=b3.
In the second example there is no such sequence.
题意:求一个n长度的t数组,满足t[i]&t[i+1] == b[i] 同时 t[i]|t[i+1] == a[i]。 a,b数组长度为n-1
枚举法,想过枚举但是没有想到是这样做的。因为t数组中,最后一个是最特殊的,只与a和b数组中的一个元素相关(自己没有发现)。同时没有发现如果确定了一个点,那么下一个点的值是唯一确定的。这样想来,其实枚举第一个也是可行的了。
同时,需要记住,如果t[i]确定了,那么与不同的t[i+1]进行或,与运算一定会得到的是不同的结果。
和之前做过的一道Fliptile有些像。
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