/* 串的堆分配存儲表示 */#include<stdio.h>#include<string.h>#include<stdlib.h>#define OK 1#define ERROR 0#define TRUE 1#define FALSE 0#define OVERFLOW -2typedef int Status;typedef struct{  char *ch; //如果是非空串，則按串長分配存儲區，否則ch為NULL  int length; //串長度}HString;/*******************************聲明部分****************************************/Status StrAssign(HString *T,char *chars);//生成一個其值等于串常量chars的串TStatus StrInsert (HString *S,int pos,HString T);//1<=pos<=StrLength(S)+1.在串S的第pos個字符之前插入串Tint StrLength(HString S);//返回S的元素個數，成為串的長度int StrCompare(HString S,HString T);//若S>T，則返回值>0,若S=T，則返回值 = 0，若S<T，則返回值<0Status ClearString(HString *S);//將S清空Status Concat(HString *T,HString S1,HString S2);//用T返回由S1和S2連接而成的新串Status SubString(HString *Sub,HString S,int pos,int len);//用Sub返回串S的第pos個字符起長度為len的子串//其中,1<= pos<= StrLength(S) 且 0<= len <= StrLength(S)-pos+1Status StrCopy(HString *T, HString S);/*******************************函數部分****************************************/Status StrAssign(HString *T,char *chars){  if((*T).ch){ //釋放舊空間    free((*T).ch);  }  int i = strlen(chars);  if(!i){ //若chars為空    (*T).ch = NULL;    (*T).length = 0;  }  else{ //chars不空    if(!((*T).ch = (char *)malloc(i * sizeof(char)))) //為T分配chars所需的存儲空間      exit(OVERFLOW);    int count;    for(count = 0;count <= i-1;count++){ //把chars存入T中      (*T).ch[count] = chars[count];      (*T).length = i;    } //for  } //else  return OK;}int StrLength(HString S){  return S.length;}int StrCompare(HString S,HString T){  int count;  for(count = 0;count < S.length && count < T.length;count++){    if(S.ch[count] != T.ch[count])      return S.ch[count] - T.ch[count];  }  return S.length - T.length;}Status ClearString(HString *S){  if((*S).ch){    free((*S).ch);    (*S).ch = NULL;  }  (*S).length = 0;  return OK;}Status Concat(HString *T,HString S1,HString S2){  if((*T).ch){ //釋放舊空間    free((*T).ch);  }  if(!((*T).ch = (char *)malloc((S1.length+S2.length)* sizeof(char))))    exit(OVERFLOW);  int count,cnt;  for(count = 0;count <= S1.length;count++){ //把S1存入T中    (*T).ch[count] = S1.ch[count];  }  (*T).length = S1.length + S2.length; //更改T的長度為兩串之和  for(count = S1.length,cnt = 0;count <= (*T).length;count++,cnt++){    (*T).ch[count] = S2.ch[cnt]; //把S2存入T中  }  return OK;}Status SubString(HString *Sub,HString S,int pos,int len){  if(pos<1 || pos>S.length || len<0 || len >S.length-pos+1)    return ERROR;  if((*Sub).ch){ //釋放舊空間    free((*Sub).ch);  }  if(!len){    (*Sub).ch = NULL;    (*Sub).length = 0; //空子串  }  else{ //完整子串    (*Sub).ch = (char *)malloc(len*sizeof(char));    int count,cnt;    for(count = 0,cnt = pos-1;count <= len-1;count++,cnt++){      (*Sub).ch[count] = S.ch[cnt];    }    (*Sub).length = len;  }//else  return OK;}Status StrInsert (HString *S,int pos,HString T){  if(pos<1 || pos >(*S).length+1)    return ERROR; //pos不合法  if(T.length){    if(!((*S).ch = (char*)realloc((*S).ch,((*S).length + T.length)*sizeof(char))))      exit(OVERFLOW);    int count,cnt;    for(count = (*S).length-1;count>= pos-1;count--){      (*S).ch[count+T.length-1] = (*S).ch[count]; //為插入T騰出位置    }    for(count = pos-1,cnt = 0;cnt<= T.length-1;count++,cnt++)    (*S).ch[count] = T.ch[cnt]; //插入T    (*S).length += T.length;  }//if  return OK;}Status StrCopy(HString *T, HString S){  int j;  if((*T).ch)    free((*T).ch);  (*T).ch = (char*)malloc(S.length * sizeof(char));  if(!(*T).ch)    exit(OVERFLOW);  for(j = 0; j < S.length; j++)    (*T).ch[j] = S.ch[j];  (*T).length = S.length;  return OK;}/*******************************主函數部分**************************************/int main(){  HString T,S,S1,S2,Sub;  char *charsT = "abcd";  char *chars1 = "abc";  char *chars2 = "AAAA";  StrAssign(&T,charsT);  StrAssign(&S,chars1);  StrAssign(&S1,chars1);  StrAssign(&S2,chars2);  int count;  printf("T的長度為：%d/n",T.length);  printf("T的內容為：");  for(count = 0;count <T.length;count++){    printf("%c",T.ch[count]);  }  printf("/n");  printf("/nStrCompare(S,T) = %d/n",StrCompare(S,T));  Concat(&T,S1,S2);  printf("/n鏈接S1，S2為T之后/n");  printf("T的長度為：%d/n",T.length);  printf("T的內容為：");  for(count = 0;count <T.length;count++){    printf("%c",T.ch[count]);  }  printf("/n");  printf("/nS的長度為：%d/n",S.length);  printf("S的內容為：");  for(count = 0;count <S.length;count++){    printf("%c",S.ch[count]);  }  printf("用Sub返回S的第1個字符起長度為2的子串/n");  SubString(&Sub,S,1,2);  printf("Sub的長度為：%d/n",Sub.length);  printf("Sub的內容為：");  for(count = 0;count <Sub.length;count++){    printf("%c",Sub.ch[count]);  }  printf("/n");  printf("/n在串S的第1個字符之前插入串T/n");  StrInsert(&S,1,T);  printf("S的長度為：%d/n",S.length);  printf("S的內容為：");  for(count = 0;count <S.length;count++){    printf("%c",S.ch[count]);  }  return 0;}