KMP算法。

#include<cstring>
#include<iostream>
using namespace std;

#define OK 1
#define ERROR 0
#define OVERFLOW -2
typedef int Status;
#define MAXSTRLEN 255 

void get_nextval(char T[], int nextval[])
{ 
    int i = 1, j = 0;
    nextval[1] = 0;
    while (i < T[0])
        if (j == 0 || T[i] == T[j])
        {
            ++i;
            ++j;
            if (T[i] != T[j])
                nextval[i] = j;
            else
                nextval[i] = nextval[j];
        } else
            j = nextval[j];
}

int Index_KMP(char S[], char T[], int pos, int next[])
{ 
    int i = pos, j = 1;
    while (i <= S[0] && j <= T[0])
        if (
20分) 
        {
            ++i;
            ++j;
        }
        else
            
20分; 
    if (j > T[0]) 
        
20分;
    else
        return 0;
}

int main()
{
    char S[MAXSTRLEN+1],T[MAXSTRLEN+1];
    char S1[MAXSTRLEN],S2[MAXSTRLEN];
    cin >> S1 >> S2;
    strcpy(&S[1],S1);
    strcpy(&T[1],S2);    
    S[0]=strlen(S1);
    T[0]=strlen(S2);
    int *p = new int[T[0]+1];
    get_nextval(T,p);
    cout<<Index_KMP(S,T,1,p);
    return 0;
}