擦,没啥好说的,这个模板至少得打10遍。。纪念自己成功的打错了。。
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define LL int
#define lson id << 1
#define rson id << 1|1
const LL M = 100008;
LL ti[M],top[M],siz[M],son[M],father[M],tp,idx,dep[M];
struct Linetree{
LL sum,l,r,mark;
LL mid(){
return (l+r)/2;
}
}node[M*4];
struct {
LL head;
}H[M];
struct {
LL v,next;
}E[M];
void add(LL u,LL v){
E[tp].v = v;
E[tp].next = H[u]. head;
H[u].head = tp++;
}
void dfs_1(LL u,LL fa){
son[u] = 0;siz[u] = 1;father[u] = fa; dep[u] = dep[fa] + 1;
for(LL i=H[u].head;i!=-1;i=E[i].next){
LL v = E[i].v;
if(v == fa)continue;
dfs_1(v,u);
siz[u] += siz[v];
if(siz[v] > siz[son[u]])son[u] = v ;
}
}
void dfs_2(LL u,LL fa){
ti[u] = idx++;
top[u] = fa;
if(son[u])dfs_2(son[u],fa);
for(LL i=H[u].head;i!=-1;i = E[i].next){
LL v = E[i].v;
if(v == father[u]||v == son[u]) continue;
dfs_2(v,v);
}
}
/* 线段树*/
void build_tree(LL id,LL l,LL r){
node[id].l = l;
node[id].r = r;
node[id].sum = 0;
if(l == r) return;
LL mid = node[id].mid();
build_tree(lson,l,mid);
build_tree(rson,mid+1,r);
}
void push_up(LL id){
node[id].sum = node[lson].sum + node[rson].sum;
}
void update(LL id,LL k,LL w){
if(node[id].l == k&&node[id].r == k){
node[id].sum = w;
return;
}
LL mid = node[id].mid();
if(k <=mid)update(lson,k,w);
else update(rson,k,w);
push_up(id);
}
LL query(LL id,LL l,LL r){
if(node[id].l == l && node[id].r == r)
return node[id].sum;
LL mid = node[id].mid();
if(r <=mid )return query(lson,l,r);
else if(l > mid)return query(rson,l,r);
else {
return query(lson,l,mid) + query(rson,mid+1,r);
}
}
LL e[M][4];
LL findmax(LL u,LL v){
LL f1 = top[u];
LL f2 = top[v];
int sum = 0;
while(f1 != f2){
if(dep[f1] < dep[f2]){
swap(f1,f2);swap(u,v);
}
sum += query(1,ti[f1],ti[u]);
u = father[f1];f1 = top[u];
}
if(u == v) return sum;
if(dep[u] > dep[v] ) swap(u,v);
sum += query(1,ti[son[u]],ti[v]);
return sum;
}
void init(){
memset(E,-1,sizeof(E));
memset(H,-1,sizeof(H));
tp = 0;
idx = 0;
memset(son,0,sizeof(son));
}
int main(){
//freopen("input.txt","r",stdin);
LL n,m,u,v,w;
while(~scanf("%d%d",&n,&m)){
init();
for(LL i=0;i<n-1;i++){
scanf("%d%d%d",&e[i][0],&e[i][1],&e[i][2]);
add(e[i][0],e[i][1]);
add(e[i][1],e[i][0]);
}
dfs_1(1,1);
dfs_2(1,1);
build_tree(1,1,idx-1);
for(LL i=0;i<n-1;i++){
if(dep[e[i][0]] > dep[e[i][1]])
swap(e[i][0],e[i][1]);
update(1,ti[e[i][1]],e[i][2]);
}
while(m --){
scanf("%d%d%d",&w,&u,&v);
if(w)printf("%d
",findmax(u,v));
else update(1,ti[e[u-1][1]],v);
}
}
}