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🐯 Data structure

Let the set of n elements be realized by using the ordered linked list of lead nodes. Let the elements of the set account for 8 bytes and the link pointer for 2 bytes. The storage density of the set is ___ (Beijing University of Posts and Telecommunications, 2013)

A, 0.8 B, n/(n+1) C, 0.8 N /(n+1) D, 0.8(n+1)/nCopy the code

parsing

Answer: C

▶️ storage density = storage capacity occupied by node data/total storage occupied by node structure


8 n 8 n + 2 n + 10 = 0.8 n n + 1 N \ frac {8} {8 n + 2 n + 10} = \ frac {0.8 n} {n + 1}

The header does not store elements, but it has 10 bytes to add.

🦁 Computer network

In Web services, the standard communication protocol between the customer and the Service is ___. (Sun Yat-sen University, 2010)

A. Simple Object Access Protocol B. Hypertext Transfer protocol C. Unified Registration and Discovery Protocol D. Remote Object Access protocolCopy the code

parsing

Answer: A,

▶️ In Web services, the communication between entities is realized based on SOAP(Simple Object Access Protocol). SOAP is the communication basis of the entire Web Service.

🐶 Operating system

In cache-main memory system, address mapping with the highest probability of block collision is ___ (Wuhan University, 2014)

A. Fully associated image B. Direct image C. Group associated image D. segment associated imageCopy the code

parsing

Answer: B

▶️ The Cache address images are direct images, group associated images, and full associated images in descending order of block collision probability.

  • Direct image is a way to map each main memory word block address to a specified address in the Cache. The hardware is simple, the address transformation speed is fast, and no replacement algorithm is required. However, the block conflict probability is high, and the Cache utilization rate is low.
  • Full associative image is the image of each main memory address to any address in the Cache. The block collision probability is low. Only when the Cache block is full, the collision will occur.
  • Group associated images are a compromise between direct images and full associated images, grouping storage space, direct images between groups, and full associated images within groups.

🦊 Computer composition principle

If the register is 8 bits and the machine number is stored in the form of complement, including one sign bit, then the decimal number -25 is represented in the register as ___ (2012年)

A. 67H
B. 99H
C. E6H
D. E7H
Copy the code

parsing

Answer: D

▶️ source to complement: find the first 1 from right to left and invert all of its left division sign bits.


Binary source code : 1001   1001 complement : 1110   0111 Hexadecimal is : E 7 Binary source code: 1001\ 1001\ complement code: 1110\ 0111 \ hex is E7

The exercises come from @Wangdao Weibo

The analysis is written by myself, if there are any questions or mistakes, please comment.

I am Mancuoj, welcome to pay attention to me and my computer entrance examination column (≧∇ Blue)