7. (10 points)You are given an empty hash table of size 13 that uses open addressing. The following sequence of keys is to be inserted: (8,2,7,18,15,19,23,15,20,16), Insert these keys using each of the following approaches. If overflow occurs, say so, and indicate the element that causes the overflow. After the insertions, search each element with equal probability, then compute the average search times for finding them: (101110ai),where ai is the comparison times of the i-th element when searching. NOTE:Hash function : H(x)=x%13; When conflict, linear probing: 0,1,2,3