CS代考计算机代写 Problem

Problem
Time Transaction Activity A B C D
0 T1 READ A
1 T2 READ B
2 T3 READ C
3 T1 READ D
4 T4 READ A
5 T4 READ B
6 T4 UPDATE B
7 T3 UPDATE C
8 T2 READ A
9 T1 UPDATE C
10 T2 READ D
11 T2 UPDATE D
12 T3 READ A