P3178 [HAOI2015]树上操作 （树链剖分模版题）

题目链接：https://www.luogu.org/problem/P3178

一定要用LL  ！！！！！

  1 #include <stdio.h>
  2 #include <cstring>
  3 #include <iostream>
  4 #include <string>
  5 #include <algorithm>
  6 #include <queue>
  7 #include <vector>
  8 #include <math.h>
  9 #include <map>
 10
 11 #define LL long long
 12 using namespace std;
 13 const int maxn = 2e5 + 10;
 14
 15 struct Edge{
 16     LL to,next;
 17 }edge[maxn*2];
 18
 19 LL head[maxn],tot;
 20
 21 void add_edge(LL u,LL v){
 22     edge[++tot] = Edge{v,head[u]};
 23     head[u] = tot;
 24 }
 25
 26 LL dep[maxn];
 27 LL fa[maxn];
 28 LL siz[maxn];
 29 LL son[maxn];
 30
 31 void dfs1(LL u,LL f){
 32     dep[u] = dep[f] + 1;
 33     fa[u] = f;
 34     siz[u] = 1;
 35     LL maxsize = -1;
 36     for (LL i=head[u];~i;i=edge[i].next){
 37         LL v = edge[i].to;
 38         if (v == f)
 39             continue;
 40         dfs1(v,u);
 41         siz[u] += siz[v];
 42         if (siz[v] > maxsize){
 43             son[u] = v;
 44             maxsize = siz[v];
 45         }
 46     }
 47 }
 48
 49 LL v[maxn];
 50 LL w[maxn];
 51 LL tim;
 52 LL dfn[maxn];
 53 LL top[maxn];
 54
 55 void dfs2(LL u,LL t){
 56     dfn[u] = ++tim;
 57     top[u] = t;
 58     w[tim] = v[u];
 59     if (!son[u])
 60         return ;
 61     dfs2(son[u],t);
 62     for (LL i=head[u];~i;i=edge[i].next){
 63         LL v = edge[i].to;
 64         if (v == fa[u] || v == son[u])
 65             continue;
 66         dfs2(v,v);
 67     }
 68 }
 69
 70 struct segment_tree{
 71     LL l,r;
 72     LL val;
 73     LL lazy;
 74 }tree[maxn*4];
 75
 76 void pushup(LL nod){
 77     tree[nod].val = (tree[nod<<1].val + tree[(nod<<1)+1].val);
 78 }
 79
 80 void pushdown(LL nod){
 81     tree[nod<<1].lazy += tree[nod].lazy;
 82     tree[(nod<<1)+1].lazy += tree[nod].lazy;
 83     tree[nod<<1].val += (tree[nod<<1].r-tree[nod<<1].l+1)*tree[nod].lazy;
 84     tree[(nod<<1)+1].val += (tree[(nod<<1)+1].r-tree[(nod<<1)+1].l+1)*tree[nod].lazy;
 85     tree[nod].lazy = 0;
 86 }
 87
 88 void build(LL l,LL r,LL nod){
 89     tree[nod].l = l;
 90     tree[nod].r = r;
 91     if (l == r){
 92         tree[nod].val = w[l];
 93         tree[nod].lazy = 0;
 94         return ;
 95     }
 96     LL mid = (l + r) >> 1;
 97     build(l,mid,nod<<1);
 98     build(mid+1,r,(nod<<1)+1);
 99     pushup(nod);
100 }
101
102 void modify(LL x,LL y,LL z,LL k=1){
103     LL l = tree[k].l,r = tree[k].r;
104     if (x <= l && y >= r){
105         tree[k].val += z * (r-l+1);
106         tree[k].lazy += z;
107         return ;
108     }
109     if (tree[k].lazy)
110         pushdown(k);
111     LL mid = (l + r) >> 1;
112     if (x <= mid){
113         modify(x,y,z,k<<1);
114     }
115     if (y > mid){
116         modify(x,y,z,(k<<1)+1);
117     }
118     pushup(k);
119 }
120
121 LL query(LL x,LL y,LL k=1){
122     LL l = tree[k].l,r = tree[k].r;
123     if (x <= l && y >= r){
124         return tree[k].val;
125     }
126     if (tree[k].lazy)
127         pushdown(k);
128     LL sum = 0;
129     LL mid = (l + r) >> 1;
130     if (x <= mid){
131         sum += query(x,y,k<<1);
132     }
133     if (y > mid){
134         sum += query(x,y,(k<<1)+1);
135     }
136     return sum;
137 }
138
139 void mson(LL x,LL z){
140     modify(dfn[x],dfn[x]+siz[x]-1,z);
141 }
142
143 LL from_query(LL x,LL y){
144     LL ret = 0;
145     while (top[x] != top[y]){
146         if (dep[top[x]] < dep[top[y]])
147             swap(x,y);
148         ret += query(dfn[top[x]],dfn[x]);
149         x = fa[top[x]];
150     }
151     if (dep[x] > dep[y])
152         swap(x,y);
153     ret += query(dfn[x],dfn[y]);
154     return ret;
155 }
156
157 int main(){
158     LL n,m;
159     scanf("%lld%lld",&n,&m);
160     memset(head,-1, sizeof(head));
161     for (LL i=1;i<=n;i++){
162         scanf("%lld",&v[i]);
163     }
164     for (LL i=1;i<=n-1;i++){
165         LL x,y;
166         scanf("%lld%lld",&x,&y);
167         add_edge(x,y);
168         add_edge(y,x);
169     }
170     dfs1(1,0);
171     dfs2(1,1);
172     build(1,n,1);
173     while (m--){
174         int op;
175         scanf("%d",&op);
176         LL x;
177         LL z;
178         if (op == 1){
179             scanf("%lld%lld",&x,&z);
180             modify(dfn[x],dfn[x],z);
181         }
182         else if (op == 2){
183             scanf("%lld%lld",&x,&z);
184             mson(x,z);
185         }
186         else if (op == 3){
187             scanf("%lld",&x);
188             printf("%lld\n",from_query(1,x));
189         }
190     }
191     return 0;
192 }

原文地址：https://www.cnblogs.com/-Ackerman/p/11459724.html