Here are a series of address references given as words addresses:
3, 7, 10, 13, 64, 48, 19, 2, 3, 11, 16, 21, 11, 3, 22, 4, 27, 6, 12, 3, 16, 17, 44, 21, and 12.
a) Assuming a direct-mapped cache with 16 one-word blocks that is initially empty, label each reference in the list as a hit or a miss and show the contents of the cache (including previous, overwritten values). You do not need to show the tag field. When done, include the hit ratio.
Cache Set V Address
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
b) Show the hits and misses and cache contents (including previous, overwritten values) for a direct- mapped cache with four-word blocks and a total size of 16 words. You do not need to show the tag field. When done, include the hit ratio.
Cache Set V Address
00
01
10
11

The idea that, for each pair of devices v and w, there’s a strict dichotomy between being “in range” or “out of range” is a simplified abstraction. more accurately, there’s a power decay function f (·) that specifies, for a pair of devices at distance δ, the signal strength f(δ) that they’ll be able to achieve on their wireless connection. (we’ll assume that f (δ) decreases with increasing δ.) we might want to build this into our notion of back-up sets as follows: among the k devices in the back-up set of v, there should be at least one that can be reached with very high signal strength, at least one other that can be reached with moderately high signal strength, and so forth. more concretely, we have values p1 ≥ p2 ≥ . . ≥ pk, so that if the back-up set for v consists of devices at distances d1≤d2≤≤dk,thenweshouldhavef(dj)≥pj foreachj. give an algorithm that determines whether it is possible to choose a back-up set for each device subject to this more detailed condition, still requiring that no device should appear in the back-up set of more than b other devices. again, the algorithm should output the back-up sets themselves, provided they can be found.\