【bzoj4034】[HAOI2015]树上操作

  1 #include <stdio.h>
  2 #include <algorithm>
  3 #define N 100001
  4 #define lson l , mid , x << 1
  5 #define rson mid + 1 , r , x << 1 | 1
  6 using namespace std;
  7 int fa[N] , deep[N] , bl[N] , si[N] , pos[N] , tot , endp[N] , n , val[N];
  8 int head[N] , to[N << 1] , next[N << 1] , cnt;
  9 long long sum[N << 3] , mark[N << 3];
 10 void add(int x , int y)
 11 {
 12     to[++cnt] = y;
 13     next[cnt] = head[x];
 14     head[x] = cnt;
 15 }
 16 void dfs1(int x)
 17 {
 18     int y , i;
 19     si[x] = 1;
 20     for(i = head[x] ; i ; i = next[i])
 21     {
 22         y = to[i];
 23         if(y != fa[x])
 24         {
 25             fa[y] = x;
 26             deep[y] = deep[x] + 1;
 27             dfs1(y);
 28             si[x] += si[y];
 29         }
 30     }
 31 }
 32 void dfs2(int x , int c)
 33 {
 34     int y , i , k = 0;
 35     pos[x] = ++tot;
 36     bl[x] = c;
 37     endp[x] = pos[x];
 38     for(i = head[x] ; i ; i = next[i])
 39     {
 40         y = to[i];
 41         if(y != fa[x] && si[y] > si[k])
 42             k = y;
 43     }
 44     if(k)
 45     {
 46         dfs2(k , c);
 47         endp[x] = max(endp[x] , endp[k]);
 48         for(i = head[x] ; i ; i = next[i])
 49         {
 50             y = to[i];
 51             if(y != fa[x] && y != k)
 52             {
 53                 dfs2(y , y);
 54                 endp[x] = max(endp[x] , endp[y]);
 55             }
 56         }
 57     }
 58 }
 59 void pushup(int x)
 60 {
 61     sum[x] = sum[x << 1] + sum[x << 1 | 1];
 62 }
 63 void pushdown(int x , int l , int r)
 64 {
 65     if(mark[x])
 66     {
 67         int mid = (l + r) >> 1;
 68         mark[x << 1] += mark[x];
 69         mark[x << 1 | 1] += mark[x];
 70         sum[x << 1] += (long long)mark[x] * (mid - l + 1);
 71         sum[x << 1 | 1] += (long long)mark[x] * (r - mid);
 72         mark[x] = 0;
 73     }
 74 }
 75 void update(int b , int e , int a , int l , int r , int x)
 76 {
 77     pushdown(x , l , r);
 78     if(b <= l && r <= e)
 79     {
 80         sum[x] += (long long)a * (r - l + 1);
 81         mark[x] = a;
 82         return;
 83     }
 84     int mid = (l + r) >> 1;
 85     if(b <= mid)
 86         update(b , e , a , lson);
 87     if(e > mid)
 88         update(b , e , a , rson);
 89     pushup(x);
 90 }
 91 long long query(int b , int e , int l , int r , int x)
 92 {
 93     pushdown(x , l , r);
 94     if(b <= l && r <= e)
 95         return sum[x];
 96     int mid = (l + r) >> 1;
 97     long long ans = 0;
 98     if(b <= mid)
 99         ans += query(b , e , lson);
100     if(e > mid)
101         ans += query(b , e , rson);
102     return ans;
103 }
104 long long solvequery(int x)
105 {
106     long long ans = 0;
107     while(bl[x] != 1)
108     {
109         ans += query(pos[bl[x]] , pos[x] , 1 , n , 1);
110         x = fa[bl[x]];
111     }
112     ans += query(1 , pos[x] , 1 , n , 1);
113     return ans;
114 }
115 int main()
116 {
117     int m , i , x , y , opt;
118     scanf("%d%d" , &n , &m);
119     for(i = 1 ; i <= n ; i ++ )
120         scanf("%lld" , &val[i]);
121     for(i = 1 ; i < n ; i ++ )
122     {
123         scanf("%d%d" , &x , &y);
124         add(x , y);
125         add(y , x);
126     }
127     dfs1(1);
128     dfs2(1 , 1);
129     for(i = 1 ; i <= n ; i ++ )
130         update(pos[i] , pos[i] , val[i] , 1 , n , 1);
131     while(m -- )
132     {
133         scanf("%d" , &opt);
134         switch(opt)
135         {
136             case 1: scanf("%d%d" , &x , &y); update(pos[x] , pos[x] , y , 1 , n , 1); break;
137             case 2: scanf("%d%d" , &x , &y); update(pos[x] , endp[x] , y , 1 , n , 1); break;
138             default: scanf("%d" , &x); printf("%lld\n" , solvequery(x));
139         }
140     }
141     return 0;
142 }