LightOJ 1348 Aladdin and the Return Journey

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 using namespace std;
  5 #define lson l,m,rt<<1
  6 #define rson m+1,r,rt<<1|1
  7 const int maxn = 30005;
  8 int siz[maxn],son[maxn],dep[maxn],tid[maxn],top[maxn],fa[maxn];
  9 int sum[maxn<<2],val[maxn];
 10 int head[maxn],cnt,lable;
 11 struct node
 12 {
 13     int v,next;
 14 }e[maxn*2];
 15 int n;
 16 void init()
 17 {
 18     memset(head,-1,sizeof(head));
 19     cnt = lable = 0;
 20 }
 21 void add(int u,int v)
 22 {
 23     e[cnt].v = v;
 24     e[cnt].next = head[u];
 25     head[u] = cnt++;
 26 }
 27 void find_heavy(int rt,int father,int depth)
 28 {
 29     int maxsize = 0;
 30     siz[rt] = 1;
 31     son[rt] = 0;
 32     fa[rt] = father;
 33     dep[rt] = depth;
 34     for(int i = head[rt];i!=-1;i = e[i].next)if(e[i].v!=father)
 35     {
 36         find_heavy(e[i].v,rt,depth+1);
 37         siz[rt]+=siz[e[i].v];
 38         if(siz[e[i].v]>maxsize)
 39             maxsize = siz[e[i].v],son[rt] = e[i].v;
 40     }
 41 }
 42 void connect(int rt,int anc)
 43 {
 44 
 45    // printf("rt=%d anc=%d\n",rt,anc);
 46     tid[rt] = ++lable;
 47     top[rt] = anc;
 48     if(son[rt])connect(son[rt],anc);
 49     for(int i = head[rt];i!=-1;i = e[i].next)
 50         if(e[i].v!=fa[rt]&&e[i].v!=son[rt])
 51             connect(e[i].v,e[i].v);
 52 }
 53 void pushup(int rt)
 54 {
 55     sum[rt] = sum[rt<<1]+sum[rt<<1|1];
 56 }
 57 void update(int pos,int val,int l,int r,int rt)
 58 {
 59     if(l==r){
 60         sum[rt] = val;
 61         return;
 62     }
 63     int m = (l+r)>>1;
 64     if(pos<=m)update(pos,val,lson);
 65     else update(pos,val,rson);
 66     pushup(rt);
 67 }
 68 int query(int L,int R,int l,int r,int rt)
 69 {
 70     if(L<=l&&r<=R)return sum[rt];
 71     int m = (l+r)>>1,ret = 0;
 72     if(L<=m)ret+=query(L,R,lson);
 73     if(m<R)ret+=query(L,R,rson);
 74     return ret;
 75 }
 76 int get(int x,int y)
 77 {
 78     int ans = 0;
 79     while(top[x]!=top[y])
 80     {
 81         if(dep[top[x]]<dep[top[y]])swap(x,y);
 82         ans+=query(tid[top[x]],tid[x],1,n,1);
 83         x = fa[top[x]];
 84     }
 85     if(dep[x]>dep[y])swap(x,y);
 86     ans+=query(tid[x],tid[y],1,n,1);
 87     return ans;
 88 }
 89 int main()
 90 {
 91    // freopen("in.txt","r",stdin);
 92     int T;scanf("%d",&T);
 93     for(int kase = 1;kase<=T;++kase)
 94     {
 95         init();
 96         scanf("%d",&n);
 97         for(int i = 1;i<=n;++i)scanf("%d",&val[i]);
 98         for(int i = 1;i<n;++i){
 99             int u,v;scanf("%d%d",&u,&v);
100             add(u+1,v+1);add(v+1,u+1);
101         }
102         find_heavy(1,1,1);
103         connect(1,1);
104         for(int i = 1;i<=n;++i)update(tid[i],val[i],1,n,1);
105         int m;scanf("%d",&m);
106         printf("Case %d:\n",kase);
107         while(m--)
108         {
109             int a,b,c;scanf("%d%d%d",&a,&b,&c);
110             b++;
111             if(a)update(tid[b],c,1,n,1);
112             else printf("%d\n",get(b,c+1));
113         }
114     }
115     return 0;
116 }