BZOJ4034——[HAOI2015]T2

1、题目大意：用一个数据结构支持树的点修改和子树修改、树上路径和

2、分析：树链剖分裸题

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
using namespace std;
#define M 1000000
#define LL long long
LL Size[M], value[M], Top[M], Fa[M], Height[M], num[M], left[M], right[M];
LL tot, ST_tot;
LL son[M], head[M], Next[M];
LL n, m;
LL q[M], lazy[M];
void init(){
    memset(head, -1, sizeof(head));
    memset(lazy, 0, sizeof(lazy));
    tot = ST_tot = 0;
    Top[1] = 1;
}
void pushdown(LL l, LL r, LL o){
    LL mid = (l + r) / 2;
    q[2 * o] += (mid + 1 - l) * lazy[o];
    q[2 * o + 1] += (r - mid) * lazy[o];
    lazy[2 * o] += lazy[o];
    lazy[2 * o + 1] += lazy[o];
    lazy[o] = 0;
}
void add(LL l, LL r, LL o, LL x, LL y, LL z){
    if(x <= l && r <= y){
        lazy[o] += z;
        q[o] += (r - l + 1) * z;
        return;
    }
    pushdown(l, r, o);
    LL mid = (l + r) / 2;
    if(x <= mid) add(l, mid, 2 * o, x, y, z);
    if(y > mid) add(mid + 1, r, 2 * o + 1, x, y, z);
    q[o] = q[2 * o] + q[2 * o + 1];
}
LL query(LL l, LL r, LL o, LL x, LL y){
    if(x <= l && r <= y) return q[o];
    pushdown(l, r, o);
    LL mid = (l + r) / 2, ret = 0;
    if(x <= mid) ret += query(l, mid, 2 * o, x, y);
    if(y > mid) ret += query(mid + 1, r, 2 * o + 1, x, y);
    return ret;
}
void insert(LL x, LL y){
    tot ++;
    son[tot] = y;
    Next[tot] = head[x];
    head[x] = tot;
} 
void dfs1(LL x, LL fa, LL height){
    Fa[x] = fa;
    Height[x] = height;
    Size[x] = 1;
    for(LL i = head[x]; i != -1; i = Next[i]) if(son[i] != fa){
        dfs1(son[i], x, height + 1);
        Size[x] += Size[son[i]];
    }
}
void dfs2(LL x, LL fa){
    ++ ST_tot;
    left[x] = ST_tot;
    num[x] = ST_tot;
    add(1, n, 1, ST_tot, ST_tot, value[x]);
    LL o = 0, ss = 0;
    for(LL i = head[x]; i != -1; i = Next[i]) if(son[i] != fa){
        if(Size[son[i]] > ss){
            ss = Size[son[i]];
            o = i;
        }
    }
    if(o != 0){
        Top[son[o]] = Top[x];
        dfs2(son[o], x);
    }
    for(LL i = head[x]; i != -1; i = Next[i]) if(son[i] != fa && o != i){
        Top[son[i]] = son[i];
        dfs2(son[i], x);
    }
    right[x] = ST_tot;
}
void real_add(LL x, LL y){
    add(1, n, 1, left[x], right[x], y);
}
void real_add1(LL x, LL y){
    add(1, n, 1, num[x], num[x], y);
}
LL real_query(LL x){
    LL y = 1;
    LL ret = 0;
    while(Top[x] != Top[y]){
        if(Height[Top[x]] < Height[Top[y]]) swap(x, y);
        ret += query(1, n, 1, num[Top[x]], num[x]);
        x = Fa[Top[x]];
    }
    if(Height[x] < Height[y]) swap(x, y);
    ret += query(1, n, 1, num[y], num[x]);
    return ret;
}
int main(){
    scanf("%lld%lld", &n, &m);
    for(LL i = 1; i <= n; i ++) scanf("%lld", &value[i]);
    init();
    for(LL i = 1; i < n; i ++){
        LL x, y;
        scanf("%lld%lld", &x, &y);
        insert(x, y);
        insert(y, x);
    }
    dfs1(1, 0, 1);
    dfs2(1, 0);
    for(LL i = 1; i <= m; i ++){
        LL op, x, a;
        scanf("%lld", &op);
        if(op == 1){
            scanf("%lld%lld", &x, &a);
            real_add1(x, a);
        }
        else if(op == 2){
            scanf("%lld%lld", &x, &a);
            real_add(x, a);
        }
        else{
            scanf("%lld", &x);
            printf("%lld\n", real_query(x));
        }
    } 
    return 0;
}