十分weak的树链剖分初步
给一棵树，实现两个功能：
①给两个节点u,v，给u,v路上的每条边权值加a
②给两个节点u,v，求u,v路上所有边的权值之和
ps:在线操作
1 #include<cstdio>
2 #include<cstring>
3 #include<iostream>
4 #include<vector>
5 using namespace std;
6
7 inline int read(){
8 char ch;
9 int re=0;
10 bool flag=0;
11 while((ch=getchar())!=‘-‘&&(ch<‘0‘||ch>‘9‘));
12 ch==‘-‘?flag=1:re=ch-‘0‘;
13 while((ch=getchar())>=‘0‘&&ch<=‘9‘) re=(re<<1)+(re<<3)+ch-‘0‘;
14 return flag?-re:re;
15 }
16
17 struct edge{
18 int to,next;
19 edge(int to=0,int next=0):
20 to(to),next(next){}
21 };
22
23 const int maxn=100001;
24
25 vector<edge> edges;
26 vector<edge> tree;
27 int head[maxn],tmp_head[maxn];
28 int n,q,root,cnt;
29 int fat[maxn],dep[maxn],siz[maxn],son[maxn],top[maxn],id[maxn];
30 //B[i]表示区间1...i变化量
31 int B[101];
32 //C[i]表示区间1...i变化量的总和，有c[i]=b[i]*i
33 int C[101];
34
35 inline void add_edge(int from,int to){
36 edges.push_back(edge(to,head[from]));
37 head[from]=++cnt;
38 edges.push_back(edge(from,head[to]));
39 head[to]=++cnt;
40 }
41
42 inline void add_tree(int from,int to){
43 tree.push_back(edge(to,tmp_head[from]));
44 tmp_head[from]=++cnt;
45 }
46
47 void init(){
48 n=read(); q=read(); root=read();
49 edges.push_back(edge(0,0));
50 cnt=0;
51 for(int i=1;i<n;i++){
52 int from=read(),to=read();
53 add_edge(from,to);
54 }
55 }
56
57 void dfs_1(int x,int fa){
58 fat[x]=fa;
59 dep[x]=dep[fa]+1;
60 siz[x]=1;
61 int maxx=0;
62 for(int ee=head[x];ee;ee=edges[ee].next)
63 if(edges[ee].to!=fa){
64 add_tree(x,edges[ee].to);
65 dfs_1(edges[ee].to,x);
66 if(siz[edges[ee].to]>maxx){
67 maxx=siz[edges[ee].to];
68 son[x]=edges[ee].to;
69 }
70 siz[x]+=siz[edges[ee].to];
71 }
72 }
73
74 void dfs_2(int x){
75 if(son[x]){
76 top[son[x]]=top[x];
77 id[son[x]]=++cnt;
78 dfs_2(son[x]);
79 }
80 for(int ee=head[x];ee;ee=tree[ee].next)
81 if(tree[ee].to!=son[x]){
82 top[tree[ee].to]=tree[ee].to;
83 id[tree[ee].to]=++cnt;
84 dfs_2(tree[ee].to);
85 }
86 }
87
88 void make(){
89 cnt=0;
90 dep[0]=0;
91 tree.push_back(edge(0,0));
92 dfs_1(root,0);
93 swap(head,tmp_head);
94 top[root]=root;
95 cnt=0;
96 dfs_2(root);
97 }
98
99 void ADD_B(int x, int c)
100 {
101 for (int i=x; i>0; i-=i&(-i)) B[i] += c;
102 }
103
104 void ADD_C(int x, int c)
105 {
106 for (int i=x; i<=n; i+=i&(-i)) C[i] += x * c;
107 }
108
109 int add(int left,int right,int c){
110 ADD_B(right,c); ADD_C(right,c);
111 if(left-1){
112 ADD_B(left-1,-c);
113 ADD_C(left-1,-c);
114 }
115 }
116
117 int SUM_B(int x)
118 {
119 int s = 0;
120 for(int i=x;i<=n;i+=i&(-i)) s+=B[i];
121 return s;
122 }
123
124 int SUM_C(int x)
125 {
126 int s=0;
127 for (int i=x;i;i-=i&(-i)) s+=C[i];
128 return s;
129 }
130
131 int SUM(int x)
132 {
133 if (x) return SUM_B(x)*x+SUM_C(x-1);
134 else return 0;
135 }
136
137 int sum(int left,int right){
138 return SUM(right)-SUM(left-1);
139 }
140
141 void cha(int u,int v,int a){
142 int f1=top[u],f2=top[v];
143 while(f1!=f2){
144 if(dep[f1]<dep[f2]){
145 swap(f1,f2);
146 swap(u,v);
147 }
148 add(id[f1],id[u],a);
149 u=fat[f1]; f1=top[u];
150 }
151 if(u==v) return;
152 if(dep[u]<dep[v]) swap(u,v);
153 add(id[son[v]],id[u],a);
154 }
155
156 int calc(int u,int v){
157 int f1=top[u],f2=top[v];
158 int len=0;
159 while(f1!=f2){
160 if(dep[f1]<dep[f2]){
161 swap(f1,f2);
162 swap(u,v);
163 }
164 len+=sum(id[f1],id[u]);
165 u=fat[f1]; f1=top[u];
166 }
167 if(u==v) return len;
168 if(dep[u]<dep[v]) swap(u,v);
169 len+=sum(id[son[v]],id[u]);
170 return len;
171 }
172
173 void solve(){
174 for(int i=0;i<q;i++){
175 int op=read(),ss=read(),tt=read();
176 if(op){
177 int a=read();
178 cha(ss,tt,a);
179 }
180 else{
181 printf("%d\n",calc(ss,tt));
182 }
183 }
184 }
185
186 int main(){
187 //freopen("temp.in","r",stdin);
188 init();
189 make();
190 solve();
191 return 0;
192 }
她会好吗 还是更烂
对我而言 是另一天
时间： 2024-08-05 07:05:46