{ int i,h,l,m,n,j=0;

for(i=0;i<S.length;i=i+2) {h=(S.ch[i]-'x'); l=(S.ch[i+1]-'z'); m=(h<<4); n=(l&0xf); T->ch[j]=m+n; j++; }

T->length=S.length/2; }

//解密

//------------模式匹配----------------------- int Index(SString S,SString T, int pos) { int i,m,n; SString sub; if (pos>=0)

{ n=StrLength(S); m=StrLength(T); i=pos; while (i<=n-m)

{ SubString(&sub,S,i,m); if (StrCompare(sub,T)!=0) i++; else

return i; } }

return -1; }//穷举法

int IndexBF(SString S,SString T,int pos) {int i,j,k=-1; i= pos; j = 0;

while( i<S.length && j<T.length){

if(S.ch[i] == T.ch[j]){ i++; j++; } else{ i = i-j+1; j =0; } }

if(j>=T.length) k=i-T.length; return k; }

//BF算法

void get_next(SString T, int next[]) {int j,k;

next[0]=-1; next[1] = 0; j = 1;k=0;

while( j<T.length){ if(T.ch[j]==T.ch[k])

{k++;j++;next[j]=k;}