uoj274 温暖会指引我们前行

来源：互联网发布：java web项目案例编辑：程序博客网时间：2024/04/29 19:38
显然只需要维护最大生成树，LCT即可。
#include<cstdio>#include<algorithm>using namespace std;const int maxn=800010;void pause(){}int rd(){    int x=0;    char c=getchar();    while (c<'0'||c>'9') c=getchar();    while (c>='0'&&c<='9')    {        x=x*10+c-'0';        c=getchar();    }    return x;}char rdc(){    char c=getchar();    while (c<'a'||c>'z') c=getchar();    return c;}int fa[maxn],son[maxn][2],sum[maxn],mnid[maxn],inv[maxn],u[maxn],v[maxn],t[maxn],l[maxn],sta[maxn],in[maxn],n,q,tot;void down(int u){    if (inv[u])    {        swap(son[u][0],son[u][1]);        if (son[u][0]) inv[son[u][0]]^=1;        if (son[u][1]) inv[son[u][1]]^=1;        inv[u]=0;    }}void up(int u){    sum[u]=sum[son[u][0]]+sum[son[u][1]]+(u>n?l[u-n]:0);    if (mnid[son[u][0]]!=-1&&(mnid[son[u][1]]==-1||t[mnid[son[u][0]]]<t[mnid[son[u][1]]])) mnid[u]=mnid[son[u][0]];    else mnid[u]=mnid[son[u][1]];    if (u>n&&(mnid[u]==-1||t[u-n]<t[mnid[u]])) mnid[u]=u-n;}int isroot(int u){    return son[fa[u]][0]!=u&&son[fa[u]][1]!=u;}void rot(int u,int f){    int v=son[u][f],x=son[v][f^1],y=fa[u];    if (son[y][0]==u) son[y][0]=v;    if (son[y][1]==u) son[y][1]=v;    fa[v]=y;    son[v][f^1]=u;    fa[u]=v;    son[u][f]=x;    if (x) fa[x]=u;    up(u);    up(v);}void splay(int u){    int t=u,x,fx,y,fy,top=0;    while (t)    {        sta[++top]=t;        if (isroot(t)) break;        t=fa[t];    }    for (;top;top--)        down(sta[top]);    while (!isroot(u))    {        x=fa[u];        fx=son[x][1]==u;        if (isroot(x)) rot(x,fx);        else        {            y=fa[x];            fy=son[y][1]==x;            if (fx==fy) rot(y,fy),rot(x,fx);            else rot(x,fx),rot(y,fy);        }    }}void access(int u){    int v=0,t=u;    while (u)    {        splay(u);        son[u][1]=v;        if (v) fa[v]=u;        up(u);        v=u;        u=fa[u];    }    splay(t);}void makeroot(int u){    access(u);    inv[u]=1;}void link(int u,int v){    makeroot(u);    fa[u]=v;}void cut(int u,int v){    makeroot(u);    access(v);    fa[u]=son[v][0]=0;    up(v);}int main(){    //freopen("b.in","r",stdin);    int x,y,id;    char c;    n=rd();    q=rd();    for (int i=0;i<=n;i++) mnid[i]=-1;    while (q--)    {        c=rdc();        if (c=='f')        {            id=rd()+1;            //if (id==2) pause();            mnid[id+n]=-1;            u[id]=rd()+1;            v[id]=rd()+1;            t[id]=rd();            l[id]=rd();            sum[id+n]=l[id];            mnid[id+n]=id;            makeroot(u[id]);            access(v[id]);            if (!isroot(u[id]))            {                x=mnid[v[id]];                if (t[id]>t[x])                {                    cut(u[id],x+n);                    cut(v[id],x+n);                    link(u[id],id+n);                    link(v[id],id+n);                    in[x]=0;                    in[id]=1;                }            }            else            {                link(u[id],id+n);                link(v[id],id+n);                in[id]=1;            }        }        else if (c=='m')        {            x=rd()+1;            y=rd()+1;            if (x==y)            {                printf("0\n");                continue;            }            makeroot(x);            access(y);            if (!isroot(x)) printf("%d\n",sum[y]);            else printf("-1\n");        }        else        {            id=rd()+1;            x=rd();            if (in[id])            {                cut(u[id],id+n);                cut(v[id],id+n);                sum[id+n]=l[id]=x;                link(u[id],id+n);                link(v[id],id+n);            }        }    }}
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