I. Overall development of Project C as shown
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Two. Analysis of each step
1. Requirements Document Analysis, this example with an electronic dictionary as an example
List each requirement and every feature of each requirement, and summarize it into a single table.
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2. Design data structure
Design data structure, that is, to determine the type of abstract data, data storage methods, first think of multiple scenarios, and then compare the pros and cons of each scheme
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1 /* 2 Solution 1 3 uses three-dimensional arrays, 110000 is the number of words, 2 bits per word corresponds to 2 rows, and 100 indicates the number of characters each row can store, 4 Because the stack space is up to 1M, this is not possible and consumes CPU resources 5 word[i][2][100] represents a word and an explanation 6 */ 7 char word[ 110000][2][100];// 8 /* 9 scenario 210 uses a structure that represents a word, key stores words, trans storage 11 All words are stored in a dynamic array of malloc allocations, and because each word is different in length, the interpretation of each word is different,12 so the length of the key is too small to meet the demand, too large to create a waste of storage space 13 */14 struct word{15 char key[100];//Word 16 char trans[100];//words corresponding to the interpretation of 17 };18 /*19 scheme three 20 use struct, but the member is a pointer, according to the actual size of words and explanations allocated memory, memory footprint small 21 Cons: Explanations are not detailed enough because a word corresponds to multiple interpretations of the 22 */23 struct word{24 char *key;//word pointer , pointing to a malloc allocated memory 25 char *trans;//explanatory pointer 26 };27 /*28 scenario four 29 30 */31 struct word{32 char *key;//A word pointer using the struct body, Points to a malloc allocated memory 33 int count_trans;//Each word corresponds to the number of interpretations 34 char **trans;//the array of character pointers that hold the explanation 35 };
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3. Draw the program overall flow chart according to demand
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4. Analyze the storage structure of the data type, such as
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5. Defining Common variables
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1/********* define common global Variables *****************/2/* 3 give a new name to the struct type: Word 4 */5 typedef struct WORD SWORD; 6/********* struct pointer, ******/7 SWORD * DICT, pointing to the thesaurus struct array; 8/*********** text Thesaurus file name *********************/9 char *dicttxtname = "Dict.txt"; 10/*********** binary thesaurus file name ***************** /11 char *dictbitname = "Dict.dat"; 12/************ number of thesaurus, struct array length ***************/13 int.
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C Language Project development process