KMP算法模板

void getFail(char* P, int* f)
{
int m = strlen(P);
f[0] = 0;
f[1] = 0;
for(int i = 1; i < m; i++)
{
int j = f[i];
while(j && P[i] != P[j])
{
j = f[j];
}
f[i + 1]=P[i]==P[j]?j+1:0;
}
}

int find(char* T, char*P, int*f)
{
int n = strlen(T), m = strlen(P);
getFail(P, f);
int j = 0;
for(int i = 0; i < n; i++)
{
while(j && P[j] != T[i])
{
j = f[j];
}
if(P[j] == T[i])
{
j++;
}
if(j == m)
{
return i - m + 1;
}
}
return -1;
}