字符串处理
- 功能描述：从键盘输入一个文本行后，为用户提供菜单选择，实现字符串一些操作——显示文本行、查找并替换指定子串、删除指定子串、统计指定子串数目。
- 实现代码：
1 #include<stdio.h> 2 #include<string.h> 3 #include<stdlib.h> 4 #pragma warning(disable:4996) 5 6 #define NUM 256 7 8 void displayMenu(); 9 int choiceItem(); 10 void searchReplace(char *buf, char *s, char *t); 11 void deleteString(char *buf, char *s); 12 int totle(char *buf, char *s); 13 14 main() 15 { 16 char buf[NUM]; 17 char s[80], t[80]; 18 int choice; 19 20 system("cls"); 21 printf("Enter a text line : "); /*输入待操作文本行*/ 22 gets(buf); 23 do{ 24 choice = choiceItem(); /*选择菜单项*/ 25 switch (choice){ 26 case 1: 27 printf("Search:"); 28 gets(s); 29 printf(" Replace:"); 30 gets(t); 31 searchReplace(buf, s, t); 32 printf(" The result is %s ", buf); 33 break; 34 case 2: 35 printf(" Delete:"); 36 gets(s); 37 deleteString(buf, s); 38 printf(" The result is %s ", buf); 39 break; 40 case 3: 41 printf(" Search:"); 42 gets(s); 43 printf(" The counts of %s is %d ", s, totle(buf, s)); 44 break; 45 case 4: 46 printf(" The string is %s ", buf); 47 break; 48 } 49 } while (choice != 0); 50 printf(" Bey!"); 51 } 52 53 void displayMenu() /*显示菜单*/ 54 { 55 printf(" ==========MENU=========== "); 56 printf("1............Search/Replace"); 57 printf(" 2............Delete"); 58 printf(" 3............Totle"); 59 printf(" 4............Display"); 60 printf(" 0............Exit "); 61 printf(" Choice: "); 62 } 63 64 int choiceItem() /*菜单选择*/ 65 { 66 int choice; 67 char line[80]; 68 69 do{ 70 displayMenu(); 71 gets(line); 72 choice = atoi(line); /*将字符串转化为整型*/ 73 } while (choice<0 || choice>4); 74 return choice; 75 } 76 77 void searchReplace(char *buf, char *s, char *t) /*查找替换子串*/ 78 { 79 char m[256]; /*内部缓冲区*/ 80 char *searchPtr = NULL; 81 do{ 82 searchPtr = strstr(buf, s); /*查找子串*/ 83 if (searchPtr != NULL){ 84 strcpy(m, searchPtr + strlen(s)); /*将子串后面的字符串备份到m中*/ 85 strcpy(searchPtr, t); 86 strcpy(searchPtr + strlen(t), m); 87 } 88 } while (searchPtr != NULL); 89 } 90 91 void deleteString(char *buf, char *s) /*删除子串*/ 92 { 93 char *searchPtr = NULL; 94 do{ 95 searchPtr = strstr(buf, s); /*查找子串*/ 96 if (searchPtr != NULL){ 97 strcpy(searchPtr, searchPtr + strlen(s)); 98 } 99 } while (searchPtr != NULL); 100 } 101 102 int totle(char *buf, char *s) /*统计子串出现的次数*/ 103 { 104 int n = 0; 105 char *searchPtr = NULL; 106 do{ 107 searchPtr = strstr(buf, s); /*查找子串*/ 108 if (searchPtr != NULL){ 109 n++; 110 buf = searchPtr + strlen(s); /*改变查找的初始位置*/ 111 } 112 } while (searchPtr != NULL); 113 return n; 114 }