2019年6月多校联训b层Day 2 test 问题 A: AC

大水题，不过考试时我想到的是KMP

#include<bits/stdc++.h>
using namespace std;
const int maxn=1e6+7;
char s1[maxn],s2[maxn];
bool flag1,flag2;
int fail[maxn];
int fail1[maxn];
int len1,len2;
char test[maxn];
char test1[maxn];
int suma[maxn];
int sumc[maxn];
int sum1a[maxn];
int sum1c[maxn];
int ans1,ans2;
void pre()
{
    fail[1]=0;
    fail[2]=0;
    fail1[1]=0;
    fail1[2]=0;
}
void kmp1()
{
    int ans=0,j=0;
    int l1=strlen(test+1);
    for(int i=1;i<=len1;i++)
    {
        while(j>0&&test[j+1]!=s1[i]) j=fail[j];
        if(test[j+1]==s1[i]) j++;
        if(j==l1) 
        {
            ans++;
            suma[ans]=i-l1+1;   
        }
    }
    ans1=ans;
}
void kmp2()
{
    int ans=0,j=0;
    int l2=strlen(test1+1);
    for(int i=1;i<=len1;i++)
    {
        while(j>0&&test1[j+1]!=s1[i]) j=fail1[j];
        if(test1[j+1]==s1[i]) j++;
        if(j==l2)
        {
            ans++;
            sum1c[ans]=i-l2+1;
        }
    }
    ans2=ans;
}
bool check()
{
    for(int i=1;i<=ans1;i++)
    {
        for(int j=1;j<=ans2;j++)
        {
            if(abs(suma[i]-sum1c[j])>1){
                return true;
            } 
        }
    }
    return false;
}
int main()
{
    while(scanf("%s",s1+1)!=EOF)
    {
        memset(fail1,0,sizeof(fail1));
        memset(fail,0,sizeof(fail));
        len1=strlen(s1+1);
        test[1]='A';
        test[2]='C';
        test1[1]='C';
        test1[2]='A';
        pre();
        kmp1();
        kmp2();
        if(check()) printf("YES\n");
        else printf("NO\n");
    }
    return 0;
}