KMP算法详解

#include<stdio.h>
#include<string.h>
void makeNext(const char P[],int next[])
{
int q,k;
int m = strlen(P);
next[0] = 0;
for (q = 1,k = 0; q < m; ++q)
{
while(k > 0 && P[q] != P[k])
k = next[k-1];
if (P[q] == P[k])
{
k++;
}
next[q] = k;
}
}

int kmp(const char T[],const char P[],int next[])
{
int n,m;
int i,q;
n = strlen(T);
m = strlen(P);
makeNext(P,next);
for (i = 0,q = 0; i < n; ++i)
{
while(q > 0 && P[q] != T[i])
q = next[q-1];
if (P[q] == T[i])
{
q++;
}
if (q == m)
{
printf("Pattern occurs with shift:%d\n",(i-m+1));
}
}
}

int main()
{
int i;
int next[20]={0};
char T[] = "ababxbababcadfdsss";
char P[] = "abcdabd";
printf("%s\n",T);
printf("%s\n",P );
// makeNext(P,next);
kmp(T,P,next);
for (i = 0; i < strlen(P); ++i)
{
printf("%d ",next[i]);
}
printf("\n");

return 0;
}