light1348Aladdin and the Return Journey树链剖分

点更新模版题，线段树 建树的时候没写更新，交了几十次吧。

#include<iostream>

#include<cstdio>

#include<cstring>

#include<map>

#include<vector>

#include<stdlib.h>

using namespace std;

#define lson l,mid,rt<<1

#define rson mid+1,r,rt<<1|1

typedef long long LL;

const int maxn = 333333;

int son[maxn], size[maxn], head[maxn], deep[maxn], pos[maxn], vis[maxn], top[maxn];

int father[maxn];

int val[maxn];

int sum[maxn << 2];

struct Node

{

    int next; int to;

}e[maxn * 2];

int len, z;



void init(int x)

{

    size[x] = 1;son[x] = 0;

    for(int i=head[x];i!=-1;i=e[i].next){

        int cc=e[i].to;

        if(cc==father[x]) continue;

        deep[cc] = deep[x]+1;

        father[cc] = x;

        init(cc);

        size[x]+=size[cc];

        if(size[son[x]]<size[cc]) son[x] = cc;

    }

}

void dfs(int x, int tp)

{

    pos[x] = ++z; vis[z] = x; top[x] = tp;

    if (son[x]) dfs(son[x], tp);

    for (int i = head[x]; i != -1; i = e[i].next){

        int cc = e[i].to;

        if (cc == father[x] || cc == son[x]) continue;

        dfs(cc,cc);

    }

}



void add(int from, int to)

{

    e[len].to = to;

    e[len].next = head[from];

    head[from] = len++;

}





void up(int rt)

{

    sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];

}

void build(int l, int r, int rt)

{

    if (l == r){

       // printf("%d %d\n",l,val[vis[l]]);

        sum[rt] = val[vis[l]]; return;

    }

    int mid = (l + r) >> 1;

    build(lson);

    build(rson);

    up(rt);

}



void update(int key, int ans, int l, int r, int rt)

{

    if (l == r){

        sum[rt] = ans; return;

    }

    int mid = (l + r) >> 1;

    if (key <= mid) update(key, ans, lson);

    else update(key, ans, rson);

    up(rt);

}



int ask(int L, int R, int l, int r, int rt)

{

    if (L <= l&&r <= R) return sum[rt];

    int mid = (l + r) >> 1;

    int ans = 0;

    if (L <= mid) ans += ask(L, R, lson);

    if (R > mid) ans += ask(L, R, rson);

    return ans;

}



int gao(int x, int y)

{

    int ans = 0;

    int fx = top[x]; int fy = top[y];

    while (fx != fy){

        if (deep[fx] < deep[fy]){

            swap(x, y); swap(fx, fy);

        }

        ans += ask(pos[fx], pos[x], 1, z, 1);

        x = father[fx]; fx = top[x];

    }

    if (deep[x]>deep[y]) swap(x, y);

    ans += ask(pos[x], pos[y], 1, z, 1);

    return ans;

}



int main()

{

    int t;

    int n;

    int a, b, c;

    int Icase = 0;

    scanf("%d",&t);

    int q;

    while (t--){

        scanf("%d",&n);

        len = 0; z = 0; memset(head, -1, sizeof(head));



        for (int i = 1; i <= n; i++){

            scanf("%d", &val[i]);

        }

        for (int i = 1; i < n; i++){

            scanf("%d%d", &a, &b); add(a + 1, b + 1); add(b + 1, a + 1);

        }

        init(1);dfs(1,1);build(1,z,1);

        scanf("%d",&q);

        printf("Case %d:\n", ++Icase);

        while (q--){

            scanf("%d%d%d", &a, &b, &c);

            if (a == 0){

                printf("%d\n",gao(b+1,c+1));

            }

            else{

                update(pos[b + 1], c, 1, z, 1);

            }

        }

    }

    return 0;

}