HDU-2087-剪花布条

链接:https://vjudge.net/problem/HDU-2087

题意:

一块花布条,里面有些图案,另有一块直接可用的小饰条,里面也有一些图案。对于给定的花布条和小饰条,计算一下能从花布条中尽可能剪出几块小饰条来呢? 

思路:

KMP模板,算得时候, 当j移到尾部时,res+1,j置为0,再继续。

代码:

#include <iostream>
#include <memory.h>
#include <vector>
#include <map>
#include <algorithm>
#include <cstdio>
#include <math.h>
#include <queue>
#include <string>

using namespace std;

typedef long long LL;

const int MAXN = 1e3 + 10;

int Next[MAXN];
int lena, lenb;
string a, b;

void Get_Next()
{
    int i = 0;
    int k = -1;
    Next[i] = k;
    while (i < lenb)
    {
        if (k == -1 || b[k] == b[i])
        {
            k++;
            i++;
            if (b[k] == b[i])
                Next[i] = Next[k];
            else
                Next[i] = k;
        }
        else
            k = Next[k];
    }
}

int Kmp()
{
    int i = 0,j = 0;
    int res = 0;
    while (i < lena)
    {
        if (j == -1 || a[i] == b[j])
            i++,j++;
        else
            j = Next[j];
        if (j == lenb)
        {
            res++;
            j = 0;
        }
    }
    return res;
}

int main()
{
    while (cin >> a)
    {
        if (a[0] == '#')
            break;
        cin >> b;
        lena = (int)a.length();
        lenb = (int)b.length();
        memset(Next, 0, sizeof(Next));
        Get_Next();
        cout << Kmp() << endl;
    }

    return 0;
}

  

posted @ 2019-03-10 16:37  YDDDD  阅读(148)  评论(0编辑  收藏  举报