C++14(g++5.4) 解法, 执行用时: 31ms, 内存消耗: 13296K, 提交时间: 2020-07-14 22:55:06
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define iinf 0x3f3f3f3f
#define linf (1ll<<60)
#define eps 1e-8
#define maxn 1000010
#define maxe 1000010
#define cl(x) memset(x,0,sizeof(x))
#define rep(i,a,b) for(i=a;i<=b;i++)
#define drep(i,a,b) for(i=a;i>=b;i--)
#define em(x) emplace(x)
#define emb(x) emplace_back(x)
#define emf(x) emplace_front(x)
#define fi first
#define se second
#define de(x) cerr<<#x<<" = "<<x<<endl
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll read(ll x=0)
{
ll c, f(1);
for(c=getchar();!isdigit(c);c=getchar())if(c=='-')f=-f;
for(;isdigit(c);c=getchar())x=x*10+c-0x30;
return f*x;
}
struct KMP
{
int n, next[maxn], t[maxn];
bool cmp(int a, int b, int p){return a==b or a>p and b>p;};
void build(int *r, int len)
{
int i, j=0;
n=len;
for(i=1;i<=len;i++)t[i]=r[i]; t[len+1]=0;
for(i=2;i<=len;i++)
{
for(;j and !cmp(t[j+1],t[i],j);j=next[j]);
next[i] = cmp(t[j+1],t[i],j)?++j:0;
}
}
int move(int pos, int x)
{
for(;pos and !cmp(t[pos+1],x,pos);pos=next[pos]);
return cmp(t[pos+1],x,0) ? pos+1 : 0;
}
}kmp;
ll last[maxn], pre[maxn];
int S[maxn], T[maxn];
char s[maxn], t[maxn];
int main()
{
ll Q=read();
while(Q--)
{
ll i, j, n, m;
scanf("%s%s",s+1,t+1);
n=strlen(s+1);
m=strlen(t+1);
rep(i,0,300)last[i]=-1;
rep(i,1,n)
{
pre[i]=last[s[i]];
last[s[i]]=i;
if(islower(s[i]))S[i] = i-pre[i];
else S[i]=-s[i];
}
rep(i,0,300)last[i]=-1;
rep(i,1,m)
{
pre[i]=last[t[i]];
last[t[i]]=i;
if(islower(t[i]))T[i] = i-pre[i];
else T[i]=-t[i];
}
// de("debug1");
kmp.build(T,m);
ll ans=0, p=0;
rep(i,1,n)
{
p = kmp.move(p,S[i]);
if(p==m)ans++, p=kmp.next[p];
}
printf("%lld\n",ans);
}
return 0;
}
C++(g++ 7.5.0) 解法, 执行用时: 75ms, 内存消耗: 17176K, 提交时间: 2022-11-29 14:11:23
#include<bits/stdc++.h>
#define ull unsigned long long
#define ll long long
#define pb push_back
#define ft first
#define sd second
#define pii pair<int,int>
#define pll pair<ll,ll>
using namespace std;
const int maxn=2e6+10;
int nt[maxn],pre[maxn],pos2[maxn],pos1[maxn];
char s1[maxn],s2[maxn];
void getpre(char s[],int pos[],int n)
{
for(int i=0;i<=128;i++) pre[i]=-1;
for(int i=0;i<n;i++){
if(s[i]>='A'&&s[i]<='Z') {pos[i]=s[i]-'A'+1;continue;}
if(pre[s[i]-'a']==-1) pos[i]=-1;
else pos[i]=i-pre[s[i]-'a']+30;
pre[s[i]-'a']=i;
}
}
void getnt(int s[],int n)
{
int i=0,j=-1;
nt[0]=-1;
while(i<n){
if(j==-1||(j+30<s[i]?s[j]==-1:s[i]==s[j])) i++,j++,nt[i]=j;
else j=nt[j];
}
}
int kmp(int s[],int p[],int n,int m)
{
getnt(p,m);
int i=0,j=0,ans=0;
while(i<n){
if(j==-1||(j+30<s[i]?p[j]==-1:s[i]==p[j])) i++,j++;
else j=nt[j];
if(j==m) ans++;
}
return ans;
}
int main()
{
int t;
cin>>t;
while(t--){
memset(pos1,0,sizeof(pos1));
memset(pos2,0,sizeof(pos2));
cin>>s1>>s2;
int n=strlen(s1),m=strlen(s2);
getpre(s1,pos1,n);
getpre(s2,pos2,m);
printf("%d\n",kmp(pos1,pos2,n,m));
}
return 0;
}
C++(clang++11) 解法, 执行用时: 19ms, 内存消耗: 5368K, 提交时间: 2020-10-30 00:56:59
#include<bits/stdc++.h>
using namespace std;
const int M=1e6+9;
int n,m;
int a[M],b[M],f[M],last[209];
char s[M],t[M];
bool cmp(int x,int y,int newletter){
return x==y||(x>=newletter&&y>=newletter);
}
void work(int ans=0){
scanf("%s%s",s+1,t+1);
m=strlen(t+1);a[m+1]=0;
n=strlen(s+1);b[n+1]=0;
for(int i=1,j=0;i<=m;f[++i]=++j){
if(t[i]>'Z'){a[i]=i-last[t[i]];last[t[i]]=i;}
else a[i]=-t[i];
while(j&&!cmp(a[i],a[j],j))j=f[j];
}
memset(last,0,sizeof(last));
for(int i=1,j=1;i<=n;++i,++j){
if(s[i]>'Z'){b[i]=i-last[s[i]];last[s[i]]=i;}
else b[i]=-s[i];
while(j&&!cmp(b[i],a[j],j))j=f[j];
if(j==m)ans++;
}
memset(last,0,sizeof(last));
printf("%d\n",ans);
}
int main(){
int T;scanf("%d",&T);
while(T--)work();
return 0;
}
