先上代码
int getNextArray(char a[], int n, int *p)
{
if(NULL == a || 0 == n)
{
return -1;
}
p[0] = -1;
p[1] = 0;
int pos = 2;
int ch = 0;
while(pos < n)
{
if(a[pos] == a[ch])
{
p[pos] = p[pos - 1] + 1;
pos ++;
ch ++;
}
else if(0 != ch)
{
ch = p[ch];
}
else
{
p[pos] = 0;
pos ++;
}
}
return 0;
}
int matchIndex(char dest[],int destLen, char match[], int matchLen)
{
if(NULL == dest || NULL == match || destLen < matchLen)
{
return -1;
}
int nextArray[N]={0};
int nError = getNextArray(match, matchLen, nextArray);
if(0 != nError)
{
return -1;
}
int dIndex = 0;
int mIndex = 0;
while(dIndex < destLen && mIndex < matchLen)
{
if(dest[dIndex] == match[mIndex])
{
dIndex ++ ;
mIndex++;
}
else
{
if(mIndex < 2)
{
dIndex ++;
mIndex = 0;
}
else
{
mIndex = nextArray[mIndex-1] ;
}
}
}
if(mIndex == matchLen)
{
return dIndex - matchLen + 1;
}
else
{
return -2;
}
}
