#include "head.h"
Status StringInit(HString &s){
if(s.str){free(s.str);s.str=NULL;
}
s.length=0;
return(0);
}
void StringCreate(HString &T){
int i,j;
char chars[100];
char * c;
scanf("%s",chars);
for(i=0,c=chars;*c;++i,++c);
if(!i) { T.str =NULL; T.length =0; }
else {
if(!(T.str =(char *)malloc((i+1)*sizeof(char))))
exit(OVERFLOW);
for(j=0;j<i+1;j++) T.str[j]=chars[j];
T.length =i;
}
}
Status StringAssign(HString &S,HString T)//串的赋值
{
S.length=T.length;
S.str=new char[S.length+1];
for(int i=0;i<=S.length;i++)
S.str[i]=T.str[i];
return (0);
}
Status StringEqual(HString S,HString T)//判串相等
{int i;
for (i=0;i<S.length&&i<T.length;++i)
if(S.str[i]!=T.str[i]) return S.str[i]-T.str[i];
return S.length-T.length;
}
Status StringConcat(HString S1,HString S2,HString &T)//串连接
{//if(T.str) free(T.str);
T.length=S1.length+S2.length;
T.str=(char*)malloc((S1.length+S2.length)*sizeof(char));
for(int i=0;i<S1.length;i++)
T.str[i]=S1.str[i];
for(int j=0;j<=S2.length;i++,j++)
T.str[i]=S2.str[j];
return (0);
}
Status StringLength(HString S)//求串长
{return S.length;}
Status SubString(HString T1,int pos,int len,HString &T2)
{
int i;
if(pos<1||pos>T1.length ||len<0||len>T1.length -pos+1)
return (1);
if(!len) { T2.str =NULL; T2.length =0; }
else {
T2.str=(char *)malloc((len+1)*sizeof(char));
for(i=0;i<len;i++)
{
T2.str[i]=T1.str[pos-1+i];
T2.length =len;
}
T2.str[len]='\0';
}
return (0);
}
Status Index(HString S,HString T)//子串定位
{int i,j;
i=0;
j=0;
while(i<S.length&&j<T.length)
{if(S.str[i]==T.str[j])
{i++;j++;}
else
{i=i-j+1;j=0;}
}
if(j==(T.length))
return (i-T.length+1);
else
return 0;
}
/*Status StringDelete(HString &s,HString t){
int n,i;
for(n=0,i=1;i<=StringLength(s)-StringLength(t)+1;i++)
if(!StringEqual(SubString(s,i,StringLength(t)),t)){
HString head,tail,s3;
StringAssign(head,SubString(s,1,i-1));
StringAssign(tail,SubString(s,i+StringLength(t),StringLength(s)-i-StringLength(t)+1));
StringConcat(s3,head,tail);
StringAssign(s,s3); //把head,tail连接为新串
}
return (0);
}*/
Status StrReplace(HString T1,HString T2,HString T3,HString &T4)
{ /*子串替换*/
int i=1,j,k=0;
do {
i=Index(T1,T2); /*利用KMP算法查找子串*/
if(k==0) /*初始化T4*/
{ if(i!=1)
{
T4.str=(char *)malloc((i-1)*sizeof(char));
T4.length =i-1;
for(j=0;j<i-1 ;j++) T4.str[j]=T1.str [j];
}
else
{ T4.str =NULL; T4.length =0; }
}
else if(i!=0)
{
T4.str =(char *)realloc(T4.str ,(T4.length+i-1)*sizeof(char)); /*利用堆存储扩大T4的存储分配空间*/
for(j=0;j<i-1 ;j++)
T4.str[j+T4.length ]=T1.str [j];
T4.length +=i-1;
}
if(i!=0)
{ StringConcat(T4,T3,T4);
T1.str +=i+T2.length-1; } /*T1表示的字符串指针后移*/
k+=i;
}while(i!=0);
T1.length -=k;
StringConcat(T4,T1,T4);
return (0);
}
