KMP總結

偉大的看毛片算法！

一直沒有做總結，先貼個代碼留個紀念吧！

#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

const int N = 100000;

char p[N], f[N];
int Next[N+1];

void getnext()//獲取next數組
{
    int len = strlen(f), i, j;
    Next[0] = Next[1] = 0;

    for(int i=1; i<len; ++i)
    {
        j = Next[i];

        while(j && f[i]!=f[j])
            j = Next[j];

        Next[i+1] = f[i]==f[j] ? j+1 : 0;
    }
}

void Find()//匹配
{
    int len1 = strlen(p), len2 = strlen(f);
    int i, j = 0, sum;
    getnext();
    for(int i=0; i<len1; ++i)
    {
        while(j && p[i]!=f[j])
            j = Next[j];
        if(p[i] == f[j])
            ++j;
        if(j == len2)
        {
            ++sum;
            printf("%d\n", i-len2+1);
        }
    }
}

int main()
{
    while(~scanf("%s%s", p, f))
    {
        Find();
        memset(f, '\0', sizeof(f));
        memset(p, '\0',sizeof(p));
        memset(Next, 0, sizeof(Next));
    }

    return 0;
}

講解神馬的以後發、、、