C语言—串复杂操作

#include <stdio.h>
#include <stdlib.h>
#define  MAX_NUM 100
typedef struct str{
    char ch[MAX_NUM+1];
    int length;

}*SString;

SString initSString()	//字符串初始化
{
      SString str=(SString)malloc(sizeof(struct str));
      if(!str)
            printf("动态内存分配失败!\n");
      str->length=0;

      return str;
}

int isEmpty(SString str)	//判断字符串是否为空
{
      if(str->length==0)
      {
            return 1;
      }
      return 0;
}

SString strAssign(SString str,char s[])		//字符串赋值
{

      int i=0;
      while(s[i])
      {
            str->ch[++str->length]=s[i];
            i++;
      }
      return str;
}

void printSString(SString str)		//打印字符串
{
      int i;


      for(i=1;i<=str->length;i++)
            printf("%c",str->ch[i]);
      printf("\n");
}

SString   strCopy(SString str1,SString str2)	//字符串复制
{
      int i;
      for(i=1;i<=str2->length;i++)
      {
            str1->ch[i]=str2->ch[i];
      }
      str1->length=str2->length;
      return str1;
}
SString strCat(SString str1,SString str2)
{
      SString str3=initSString();
      int i;
      for(i=1;i<=str1->length;i++)
            str3->ch[i]=str1->ch[i];
      for(i=1;i<=str2->length;i++)
            str3->ch[i+str1->length]=str2->ch[i];
      str3->length=str1->length+str2->length;
      return str3;

}

int getStrLength(SString str)	//获取字符串的长度
{
      return str->length;
}
	
SString strInsert(SString str1,int pos,SString str2)	//在串str1的pos位置插入串str2
{
      if(pos<1||pos>str1->length)
      {
             printf("插入位置错误!\n");
             exit(0);
      }
      int i;
      for(i=pos;i<=str1->length;i++)
      {
            str1->ch[i+str2->length]=str1->ch[i];
      }
      for(i=1;i<=str2->length;i++)
      {
            str1->ch[i+pos-1]=str2->ch[i];
      }
      str1->length=str2->length+str1->length;
      return str1;
}


SString strDelete(SString str,int pos,int len)	//删除指定位置的字符
{
      if(pos<1||pos>str->length||len+pos-1>str->length)
      {
             printf("删除位置错误!\n");
             exit(0);
      }

      int i;
      for(i=pos+len;i<=str->length;i++)
      {

            str->ch[i-len]=str->ch[i];
      }
      str->length=str->length-len;
      return str;

}

SString subString(SString str,int pos,int len)	//求子串
{
      if(pos<1||pos>str->length||len+pos-1>str->length)
      {
             printf("输入位置错误!\n");
             exit(0);
      }
      int i;
      SString subStr=initSString();
      for(i=1;i<=len;i++)
      {
            subStr->ch[i]=str->ch[i+pos-1];
      }
      subStr->length=len;
      return subStr;
}

void destorySString(SString str1)	//销毁字符串
{

      free(str1);
}

int main()
{
      SString str=initSString(),str2=initSString();
      char s[100],s2[100],s3[100],s4[100];
      printf("请输入一个字符串str1:\n");
      scanf("%s",s);

      str=strAssign(str,s);
      printf("打印字符串str1:\n");
      printSString(str);

      printf("拷贝字符串str1到字符串str2\n");

      strCopy(str2,str);
      printf("打印字符串str2:\n");

      printSString(str2);

      /*SString str3=strCat(str,str2);
      printSString(str3);*/
      int insertLocation;

      printf("请输入插入位置、插入字符串str4:\n");


      scanf("%d",&insertLocation);
      scanf("%s",s4);
      SString str4=initSString();
      str4=strAssign(str4,s4);


      str=strInsert(str,insertLocation,str4);
      printf("打印插入str4后的字符串str1:");
      printSString(str);

      int delLocation,delLength;
      printf("请输入字符串str1删除字符的位置和长度:\n");
      scanf("%d %d",&delLocation,&delLength);

      strDelete(str,delLocation,delLength);
      printSString(str);

      int subLocation,subLength;
      printf("请输入字符串str1的子串位置和长度:\n");
      scanf("%d %d",&subLocation,&subLength);
      SString subStr=  subString(str,subLocation,subLength);
      printSString(subStr);

      printf("销毁字符串st1:\n");
      destorySString(str);

    return 0;
}