muuuuuuban

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快要考省选了 模板还没打 趁还有3天加油干。。。
1.MTT

//MTT
#include<bits/stdc++.h>
#define mod1 469762049
#define mod2 998244353
#define mod3 1004535809
#define N 300005
#define ll long long
using namespace std;

int a[N],b[N],mod,ans[3][N],rev[N],n,m,c[N],d[N];

inline int read()
{
    int ans=0,f=1;char c=getchar();
    while(c>'9'||c<'0') {if(c=='-') f=-1;c=getchar();}
    while(c>='0'&&c<='9') ans=(ans<<1)+(ans<<3)+(c^48),c=getchar();
    return ans*f;
}

inline int mul(int a,int b,int mod)
{
    int ans=1;
    while(b)
    {
        if(b&1) ans=(ll)ans*a%mod;
        a=(ll)a*a%mod;
        b>>=1;
    }
    return ans;
}

inline void NTT(int n,int a[],int dft,int mod)
{
    for(int i=0;i<n;++i) if(rev[i]>i) swap(a[i],a[rev[i]]);
    for(int k=1;k<n;k<<=1)
        for(int i=0,wn=mul(3,(mod-1)/(k<<1),mod);i<n;i+=(k<<1))
            for(int j=i,wnk=1;j<i+k;++j,wnk=(ll)wnk*wn%mod)
            {
                int x=a[j],y=(ll)wnk*a[j+k]%mod;
                a[j]=(x+y)%mod,a[j+k]=(x-y+mod)%mod;
            }
    if(dft==-1)
    {
        int inv=mul(n,mod-2,mod);
        a[0]=(ll)a[0]*inv%mod;
        for(int i=1;i<=n/2;++i)
        {
            a[i]=(ll)a[i]*inv%mod;
            if((i<<1)!=n) a[n-i]=(ll)a[n-i]*inv%mod;
            swap(a[i],a[n-i]);
        }
    }
}

int inv_1=mul(mod1,mod2-2,mod2),inv_1_2=mul((ll)mod1*mod2%mod3,mod3-2,mod3);

inline int get(int x)
{
    ll k=(ll)ans[0][x]+(ll)(ans[1][x]-ans[0][x]+mod2)%mod2*inv_1%mod2*mod1;
    return ((ll)(ans[2][x]-k%mod3+mod3)%mod3*inv_1_2%mod3*((ll)mod1*mod2%mod)%mod+k)%mod;
}

signed main()
{
    n=read()+1,m=read()+1,mod=read();
    for(int i=0;i<n;++i) a[i]=read();
    for(int i=0;i<m;++i) b[i]=read();
    int lim=1,l=0;
    while(lim<n+m) lim<<=1,l++;
    for(int i=0;i<lim;++i)
        rev[i]=(rev[i>>1]>>1)|((i&1)<<(l-1));
    copy(a,a+lim,c);
    copy(b,b+lim,d);
    NTT(lim,c,1,mod1);NTT(lim,d,1,mod1);
    for(int i=0;i<lim;++i) ans[0][i]=(ll)c[i]*d[i]%mod1;
    NTT(lim,ans[0],-1,mod1);
    copy(a,a+lim,c);
    copy(b,b+lim,d);
    NTT(lim,c,1,mod2);NTT(lim,d,1,mod2);
    for(int i=0;i<lim;++i) ans[1][i]=(ll)c[i]*d[i]%mod2;
    NTT(lim,ans[1],-1,mod2);
    copy(a,a+lim,c);
    copy(b,b+lim,d);
    NTT(lim,c,1,mod3);NTT(lim,d,1,mod3);
    for(int i=0;i<lim;++i) ans[2][i]=(ll)c[i]*d[i]%mod3;
    NTT(lim,ans[2],-1,mod3);
    for(int i=0;i<n+m-1;++i)
        printf("%lld ",get(i));
}

2.多项式求逆

#include<bits/stdc++.h>
#define N 300005
#define p 998244353
#define ll long long
using namespace std;

int a[N],n,b[N],c[N],rev[N];

inline int read()
{
    int ans=0,f=1;char c=getchar();
    while(c>'9'||c<'0') {if(c=='-') f=-1;c=getchar();}
    while(c>='0'&&c<='9') ans=(ans<<1)+(ans<<3)+(c^48),c=getchar();
    return ans*f;
}

inline int mul(int a,int b)
{
    int ans=1;
    while(b)
    {
        if(b&1) ans=(ll)ans*a%p;
        a=(ll)a*a%p;
        b>>=1;
    }
    return ans;
}

inline void NTT(int n,int a[],int dft)
{
    for(int i=0;i<n;++i) if(rev[i]>i) swap(a[i],a[rev[i]]);
    for(int k=1;k<n;k<<=1)
        for(int i=0,wn=mul(3,(p-1)/(k<<1));i<n;i+=(k<<1))
            for(int j=i,wnk=1;j<i+k;++j,wnk=(ll)wnk*wn%p)
            {
                int x=a[j]%p,y=(ll)a[j+k]*wnk%p;
                a[j]=(x+y)%p,a[j+k]=(x-y+p)%p;
            }
    if(dft==-1)
    {
        int inv=mul(n,p-2);
        reverse(a+1,a+n);
        for(int i=0;i<n;++i) a[i]=(ll)a[i]*inv%p;
    }
}

void work(int n,int a[],int b[])
{
    if(n==1){b[0]=mul(a[0],p-2);return;}
    work((n+1)>>1,a,b);
    int lim=1,l=0;
    while(lim<(n<<1)) lim<<=1,l++;
    for(int i=1;i<lim;++i) rev[i]=(rev[i>>1]>>1)|((i&1)<<(l-1));
    for(int i=0;i<n;++i) c[i]=a[i];
    for(int i=n;i<lim;++i) c[i]=0;
    NTT(lim,c,1),NTT(lim,b,1);//for(int i=0;i<n;++i) printf("%d ",rev[i]);puts("");
    for(int i=0;i<lim;++i) b[i]=(ll)(2ll-(ll)c[i]*b[i]%p+p)%p*b[i]%p;
    NTT(lim,b,-1);
    for(int i=n;i<lim;++i) b[i]=0;

}

int main()
{
    n=read();
    for(int i=0;i<n;++i) a[i]=read();
    work(n,a,b);
    for(int i=0;i<n;++i) printf("%d ",b[i]);
}

3.分治NTT

#include<bits/stdc++.h>
#define N 300005
#define ll long long
#define p 998244353
using namespace std;

int n,g[N],f[N],rev[N],a[N],b[N];

inline int read()
{
    int ans=0,f=1;char c=getchar();
    while(c>'9'||c<'0') {if(c=='-') f=-1;c=getchar();}
    while(c>='0'&&c<='9') ans=(ans<<1)+(ans<<3)+(c^48),c=getchar();
    return ans*f;
}

inline int mul(int a,int b)
{
    int ans=1;
    while(b)
    {
        if(b&1) ans=(ll)ans*a%p;
        a=(ll)a*a%p;
        b>>=1;
    }
    return ans;
}

inline void NTT(int n,int a[],int dft)
{
    for(int i=1;i<n;++i) if(rev[i]>i) swap(a[i],a[rev[i]]);
    for(int k=1;k<n;k<<=1)
        for(int i=0,wn=mul(3,(p-1)/(k<<1));i<n;i+=(k<<1))
            for(int j=i,wnk=1;j<i+k;++j,wnk=(ll)wnk*wn%p)
            {
                int x=a[j],y=(ll)wnk*a[j+k]%p;
                a[j]=(x+y)%p,a[j+k]=(x-y+p)%p;
            }
    if(dft==-1)
    {
        int inv=mul(n,p-2);
        reverse(a+1,a+n);
        for(int i=0;i<n;++i) a[i]=(ll)a[i]*inv%p;
    }
}

void work(int l,int r)
{
    if(l==r) return;
    int mid=l+r>>1;
    work(l,mid);
    int len=0,lim=1,n=r-l+1;
    while(lim<(n+mid-l+1)) lim<<=1,len++;
    for(int i=1;i<lim;++i) rev[i]=(rev[i>>1]>>1)|((i&1)<<(len-1));
    for(int i=0;i<(mid-l+1);++i) a[i]=f[i+l];
    for(int i=mid-l+1;i<lim;++i) a[i]=0;
//  for(int i=0;i<mid-l+1;++i) printf("%d ",a[i]);puts("");
    for(int i=0;i<n;++i) b[i]=g[i];
    for(int i=n;i<lim;++i) b[i]=0;
    NTT(lim,a,1),NTT(lim,b,1);
    for(int i=0;i<lim;++i) a[i]=(ll)a[i]*b[i]%p;
    NTT(lim,a,-1);
//  for(int i=0;i<n;++i) printf("%d ",a[i]);puts("");
    for(int i=mid-l+1;i<n;++i) f[i+l]=(f[i+l]+a[i])%p;
    work(mid+1,r);
}

int main()
{
    f[0]=1;
    n=read();
    for(int i=1;i<n;++i) g[i]=read();
    work(0,n-1);
    for(int i=0;i<n;++i) printf("%d ",f[i]);
}

4.最小圆覆盖

#include<bits/stdc++.h>
#define N 100005
#define eps 1e-10
#define ld long double
using namespace std;

int n;
ld r;
struct node{ld x,y;ld operator * (const node b) const {return x*b.x+y*b.y;};}a[N],o;

node operator - (const node a,const node b){return (node){a.x-b.x,a.y-b.y};}

node operator + (const node a,const node b){return (node){a.x+b.x,a.y+b.y};}

inline int read()
{
    int ans=0,f=1;char c=getchar();
    while(c>'9'||c<'0') {if(c=='-') f=-1;c=getchar();}
    while(c>='0'&&c<='9') ans=(ans<<1)+(ans<<3)+(c^48),c=getchar();
    return ans*f;
}

inline ld dis(node a,node b){return sqrt((a-b)*(a-b));}

inline void tt(node a,node b,node c)
{
    ld A=a.x-b.x;
    ld B=a.y-b.y;
    ld C=a.x-c.x;
    ld D=a.y-c.y;
    ld E=(a.x*a.x-b.x*b.x+a.y*a.y-b.y*b.y)/2.0;
    ld F=(a.x*a.x-c.x*c.x+a.y*a.y-c.y*c.y)/2.0;
    o=(node){(E*D-B*F)/(A*D-B*C),(C*E-A*F)/(B*C-A*D)};
    r=dis(o,a);
}

inline bool check(node a)
{
    return dis(a,o)>r+eps;
}

int main()
{
    n=read();
    double x,y;
    for(int i=1;i<=n;++i) scanf("%lf %lf",&x,&y),a[i]=(node){x,y};
    random_shuffle(a+1,a+1+n);
    o=a[1];
    for(int i=2;i<=n;++i)
        if(check(a[i]))
        {
            o=a[i],r=0;
            for(int j=1;j<i;++j)
                if(check(a[j]))
                {
                    o=a[i]+a[j];
                    o=(node){o.x/2.0,o.y/2.0};
                    r=dis(a[i],a[j])/2.0;
                    for(int k=1;k<j;++k)
                        if(check(a[k]))
                        {
                            tt(a[i],a[j],a[k]);
                        }
                }
        }
    printf("%.10lf\n%.10lf %.10lf",(double)r,(double)o.x,(double)o.y);
}

5.后缀树

#include<bits/stdc++.h>
#define N 1000005
#define inf 1000000000
using namespace std;

int to[N<<1][27],len[N<<1],n,nxt[N<<1],tot,st[N<<1],up;
long long ans,cnt[N<<1];
char s[N],s1[N];

inline int add(int sta,int l)
{
    tot++;
    st[tot]=sta;
    len[tot]=l;
    return tot;
}

long long dfs(int x,int l)
{
    if(len[x]>=inf-n) cnt[x]=1;
    for(int i=0;i<=26;++i)
        if(to[x][i])
        {
            cnt[x]+=dfs(to[x][i],l+len[to[x][i]]);
        }
    if(cnt[x]>1) ans=max(ans,(long long)l*cnt[x]);
    return cnt[x];
}

int main()
{
    scanf("%s",s+1);
    len[0]=inf;
    n=strlen(s+1);
    int lst=0,now=0,res=0;s[++n]='z'+1;
    for(int i=1;i<=n;++i)
    {
        res++;lst=0;
        while(res)
        {
            while(len[to[now][s[i-res+1]-'a']]<res) res-=len[now=to[now][s[i-res+1]-'a']];
            int ed=s[i-res+1]-'a';
            int &v=to[now][ed];
            int c=s[st[v]+res-1]-'a';
            if(!v)
            {
                v=add(i-res+1,inf);
                nxt[lst]=now;
                lst=now;
            }
            else if(c==s[i]-'a')
            {
                nxt[lst]=now;
                lst=now;
                break;
            }
            else
            {
                int u=add(st[v],res-1);
                to[u][s[i]-'a']=add(i,inf);
                to[u][c]=v;
                st[v]=st[v]+res-1;
                len[v]=len[v]-res+1;
                nxt[lst]=v=u,lst=v;
            }
            if(!now) res--;
            else now=nxt[now];
        }
    }
    dfs(0,0);
    printf("%lld",ans);
}