申論題

4. (4%) If LRU (Least Recently Used) page replacement is used with four page frames and initially all empty. Please write content of four page frames for cach time instant sequentially. How many page faults (i.e. swap outs, excluding the initial four swap ins) will occur for reference string 1234524167641542? For example: Oldest - - Newest =- - - -=＞- -  -1=＞- -12=＞-123=＞1 234=＞ 2345-=＞ ...