自定义串的实现

有限序列由0个或多个字符组成

自己的字符串在各种语言中定义，比如C ,java

现在给出一个C中顺序串的实现(PS:串不适合链表的形式，因为每个节点的数据只存储一个字符，如果需要额外的指针，空间会产生很大的浪费)

#include <stdio.h> #include <stddef.h> #include <stdlib.h> #include <string.h>  #define OK 1 #define ERROR 0 #define TRUE 1 #define FALSE 0  #define MAXSIZE 40  typedef int Status; typedef int ElemType;  //自定义一个MyString串,首字母在数组中 typedef struct {  char data[MAXSIZE];  int length; }MyString;  void PrintString(MyString S) {  printf("MyString = ");  for (int i = 0; i < S.length; i  ) {   printf("%c", S.data[i]);  }  printf("\n"); }  //生成一个值等于chars的串 Status StrAssign(MyString* S, const char* chars) {  int len = strlen(chars);  if (len == 0) {   S->data[0] = '\0';   S->length = 0;  }  else {   for (int i = 0; i < len; i  ) {    S->data[i] = chars[i];   }   S->length = len;  }  return OK; }  //复制串 Status StrCpoy(MyString* S, MyString T) {  for (int i = 0; i < T.length; i  ) {   S->data[i] = T.data[i];  }  S->length = T.length;  return OK; }  ///判断是否为空串 Status StrEmpty(MyString S) {  if (S.length == 0) {   return TRUE;  }  else {   return FALSE;  } }  //获取长度 int StrLength(MyString S) {  return S.length; }  ///比较两个串的大小 int StrCompare(MyString S, MyString T) {  int lenS = S.length;  int lenT = T.length;  ///比较相同长度的部分  for (int i = 0; i < lenS && i < lenT; i  ) {   if (S.data[i] != T.data[i]) {    return S.data[i] - T.data[i];   }  }  //相同长度的部分相同，长度较长的字符串较大  return lenS - lenT; }  ///清空字符串 Status ClearnString(MyString* S) {  S->length = 0;  return OK; }  //字符串拼接 Status Strcat(MyString* S, MyString S1, MyString S2) {  //拷贝S1  for (int i = 0; i < S1.length; i  ) {   S->data[i] = S1.data[i];  }  if (S1.length   S2.length > MAXSIZE) {   //拷贝S2的部分内容   for (int j = S1.length; j < MAXSIZE; j  ) {    S->data[j] = S2.data[j - S1.length];   }   S->length = MAXSIZE;  }  else {   //拷贝S2的全部内容   for (int j = 0; j < S2.length; j  ) {    S->data[j   S1.length] = S2.data[j];   }   S->length = S1.length   S2.length;  }  return OK; }  Status SubString(MyString* Sub, MyString S, int pos, int len) {  if (pos < 1 || pos > S.length) {   printf("SubString pos out of range\n");   return ERROR;  }  if (len < 0 || len > S.length - pos   1) {   printf("SubString len is illegal or to long\n");   return ERROR;  }   for (int i = 0; i < len; i  ) {   Sub->data[i] = S.data[pos - 1   i];  }  Sub->length = len;  return OK; }  ////返回子串在主串中的位置 int Index(MyString S, MyString Sub, int pos) {  if (Sub.length > S.length) {   printf("Sub is longer than S\n");   return 0;  }  if (pos < 1 || S.length == 0 || Sub.length == 0) {   printf("Index pos out of range\n");   return 0;  }  int posS = pos - 1;  int posSub = 0;  while (posS < S.length && posSub < Sub.length) {   if (S.data[posS] == Sub.data[posSub]) {    //等待继续    posS  ;    posSub  ;   }   else {    //不匹配，主串的起始位置 1,子串位置为零    posS = posS - posSub   1;    posSub = 0;   }  }   if (posSub == Sub.length) {   return posS - posSub   1;  }  else {   return 0;  } }  Status StrInsert(MyString* S, int pos, MyString T) {  if (pos < 1 || pos > S->length   1) {   printf("StrInsert pos illegal\n");   return ERROR;  }   if (S->length   T.length <= MAXSIZE) {   //完全插入   for (int i = S->length; i >= pos; i--) {    ///主串元素后移    S->data[i   T.length - 1] = S->data[i - 1];   }   for (int j = pos; j < pos   T.length; j  ) {    ////插入元素    S->data[j - 1] = T.data[j - pos];   }   S->length  = T.length;  } else {   //部分插入   for (int i = MAXSIZE; i >= pos; i--) {    ///主串元素后移    S->data[i - 1] = S->data[i - 1 - T.length];   }   for (int j = pos; j < pos   T.length; j  ) {    ////插入元素    //注意,这是隐藏的bug,就是pos t-1可能超出数组的范围，示例代码不考虑这种情况，仅提示    S->data[j - 1] = T.data[j - pos];   }   S->length = MAXSIZE;  }  return OK; }  Status StrDelete(MyString *S, int pos, int len) {  if (pos < 1 || pos >(S->length - len   1) || len < 0) {   printf("StrDelete illegal argument\n");   return FALSE;  }   for (int i = pos   len; i <= S->length; i  ) {   S->data[i - len - 1] = S->data[i - 1];  }  S->length -= len;  return OK; }  //初始条件: 串S,target和src存在,target是非空串 //操作结果： 用src替换主串S中出现的和target不重叠于不重叠 Status Replace(MyString *S, MyString target, MyString src) {  if (StrEmpty(target)) {   printf("Replace target cannot be empty string");   return ERROR;  }  int curPos = 1;  do {   curPos = Index(*S,target,curPos);   if (curPos) {    ///说明找到一致的元素    StrDelete(S,curPos,target.length);    StrInsert(S,curPos,src);    curPos  = src.length;   }  } while (curPos);  return OK; }       int main(void) {  MyString S;  //printf("String is empty = %d\n", StrEmpty(S));  StrAssign(&S,"123456789");  rintf("String is empty = %d\n", StrEmpty(S));
	printf("String length = %d\n",StrLength(S));
	PrintString(S);

	
	MyString newString;
	//复制串
	//StrCpoy(&newString,S);
	//StrAssign(&newString, "1234567");

	//比较串
	//printf("String compare:%d", StrCompare(newString,S));
	//PrintString(newString);

	//拼接
	//MyString hpk;
	//StrAssign(&hpk,"hpk");
	//MyString hyj;
	//StrAssign(&hyj, "hyj");
	//Strcat(&S,hpk,hyj);

	//取得子串
	//MyString substring;
	//SubString(&substring,S,2,4);
	//PrintString(substring);

	//获取子串位置
	//MyString substring;
	//StrAssign(&substring,"456");
	//int pos = Index(S,substring,2);
	//printf("substring pos = %d\n",pos);

	//插入
	//MyString substring;
	//StrAssign(&substring,"hpk");
	//StrInsert(&S,10,substring);
	//PrintString(S);

	//删除
	//StrDelete(&S,1,3);
	//PrintString(S);

	//替换
 	MyString src;
	StrAssign(&src,"hpk");
	MyString dest;
	StrAssign(&dest, "234");
	Replace(&S,dest,src);
	PrintString(S);

	return 0;
}