luogu3178 [HAOI2015]树上操作

Posted poorpool

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了luogu3178 [HAOI2015]树上操作相关的知识,希望对你有一定的参考价值。

裸题

#include <iostream>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, m, ecnt, hea[100005], dep[100005], top[100005], idx[100005], cnt;
int fa[100005], siz[100005], son[100005], uu, vv;
ll w[100005], wt[100005], ww;
struct Edge{
    int too, nxt;
}edge[200005];
void add_edge(int fro, int too){
    edge[++ecnt].nxt = hea[fro];
    edge[ecnt].too = too;
    hea[fro] = ecnt;
}
void dfs1(int x, int f){
    dep[x] = dep[f] + 1;
    fa[x] = f;
    siz[x] = 1;
    int maxSon=-1;
    for(int i=hea[x]; i; i=edge[i].nxt){
        int t=edge[i].too;
        if(t==f)    continue;
        dfs1(t, x);
        siz[x] += siz[t];
        if(siz[t]>maxSon){
            maxSon = siz[t];
            son[x] = t;
        }
    }
}
void dfs2(int x, int topf){
    top[x] = topf;
    idx[x] = ++cnt;
    wt[cnt] = w[x];
    if(!son[x]) return ;
    dfs2(son[x], topf);
    for(int i=hea[x]; i; i=edge[i].nxt){
        int t=edge[i].too;
        if(t==fa[x] || t==son[x])   continue;
        dfs2(t, t);
    }
}
struct SGT{
    ll sum[400005];
    ll tag[400005];
    void build(int o, int l, int r){
        if(l==r)    sum[o] = wt[l];
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            if(l<=mid)  build(lson, l, mid);
            if(mid<r)   build(rson, mid+1, r);
            sum[o] = sum[lson] + sum[rson];
        }
    }
    void pushDown(int o, int l, int r, int lson, int rson, int mid){
        tag[lson] += tag[o];
        tag[rson] += tag[o];
        sum[lson] += tag[o] * (mid-l+1);
        sum[rson] += tag[o] * (r-mid);
        tag[o] = 0;
    }
    void update(int o, int l, int r, int x, int y, ll k){
        if(l>=x && r<=y){
            sum[o] += (r-l+1) * k;
            tag[o] += k;
        }
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            if(tag[o])  pushDown(o, l, r, lson, rson, mid);
            if(x<=mid)  update(lson, l, mid, x, y, k);
            if(mid<y)   update(rson, mid+1, r, x, y, k);
            sum[o] = sum[lson] + sum[rson];
        }
    }
    ll query(int o, int l, int r, int x, int y){
        if(l>=x && r<=y)    return sum[o];
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            ll ans=0;
            if(tag[o])  pushDown(o, l, r, lson, rson, mid);
            if(x<=mid)  ans += query(lson, l, mid, x, y);
            if(mid<y)   ans += query(rson, mid+1, r, x, y);
            return ans;
        }
    }
}sgt;
ll queryRange(int uu, int vv){
    ll ans=0;
    while(top[uu]!=top[vv]){
        if(dep[top[uu]]<dep[top[vv]])   swap(uu, vv);
        ans += sgt.query(1, 1, n, idx[top[uu]], idx[uu]);
        uu = fa[top[uu]];
    }
    if(dep[uu]>dep[vv]) swap(uu, vv);
    ans += sgt.query(1, 1, n, idx[uu], idx[vv]);
    return ans;
}
signed main(){
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        scanf("%lld", &w[i]);
    for(int i=1; i<n; i++){
        scanf("%d %d", &uu, &vv);
        add_edge(uu, vv);
        add_edge(vv, uu);
    }
    dep[1] = 1;
    dfs1(1, 0);
    dfs2(1, 1);
    sgt.build(1, 1, n);
    while(m--){
        scanf("%d", &uu);
        if(uu==1){
            scanf("%d %lld", &vv, &ww);
            sgt.update(1, 1, n, idx[vv], idx[vv], ww);
        }
        if(uu==2){
            scanf("%d %lld", &vv, &ww);
            sgt.update(1, 1, n, idx[vv], idx[vv]+siz[vv]-1, ww);
        }
        if(uu==3){
            scanf("%d", &vv);
            printf("%lld\n", queryRange(1, vv));
        }
    }
    return 0;
}

以上是关于luogu3178 [HAOI2015]树上操作的主要内容,如果未能解决你的问题,请参考以下文章

「Luogu P3178」[HAOI2015]树上操作

luogu P3178 [HAOI2015]树上操作

洛谷——P3178 [HAOI2015]树上操作

P3178 [HAOI2015]树上操作 (树链剖分模版题)

P3178 [HAOI2015]树上操作

[HAOI2015]树上操作