边权
线段树
1 const int MAXN=10005; 2 struct Edge 3 { 4 int to, next; 5 }edge[MAXN<<1]; 6 int head[MAXN], tot; 7 int top[MAXN]; 8 int fa[MAXN]; 9 int deep[MAXN]; 10 int num[MAXN]; 11 int p[MAXN]; 12 int fp[MAXN]; 13 int son[MAXN]; 14 int pos; 15 void init() 16 { 17 tot=0; 18 memset(head, -1, sizeof(head)); 19 pos=0; 20 memset(son, -1, sizeof(son)); 21 } 22 void addedge(int u, int v) 23 { 24 edge[tot].to=v; 25 edge[tot].next=head[u]; 26 head[u]=tot++; 27 } 28 void dfs1(int u, int pre, int d) 29 { 30 deep[u]=d; 31 fa[u]=pre; 32 num[u]=1; 33 for(int i=head[u];i!=-1;i=edge[i].next) 34 { 35 int v=edge[i].to; 36 if(v!=pre) 37 { 38 dfs1(v, u, d+1); 39 num[u]+=num[v]; 40 if(son[u]==-1 || num[v]>num[son[u]]) 41 son[u]=v; 42 } 43 } 44 } 45 void getpos(int u, int sp) 46 { 47 top[u]=sp; 48 p[u]=pos++; 49 fp[p[u]]=u; 50 if(son[u]==-1) 51 return ; 52 getpos(son[u], sp); 53 for(int i=head[u];i!=-1;i=edge[i].next) 54 { 55 int v=edge[i].to; 56 if(v!=son[u] && v!=fa[u]) 57 getpos(v, v); 58 } 59 } 60 61 struct node 62 { 63 int l, r; 64 int Max; 65 }seg[MAXN*3]; 66 void build(int i, int l, int r) 67 { 68 seg[i].l=l; 69 seg[i].r=r; 70 seg[i].Max=0; 71 if(l==r) 72 return ; 73 int mid=(l+r)>>1; 74 build(i<<1, l, mid); 75 build((i<<1)|1, mid+1, r); 76 } 77 void pushup(int i) 78 { 79 seg[i].Max=max(seg[i<<1].Max, seg[(i<<1)|1].Max); 80 } 81 void update(int i, int k, int val) 82 { 83 if(seg[i].l==k && seg[i].r==k) 84 { 85 seg[i].Max=val; 86 return ; 87 } 88 int mid=(seg[i].l+seg[i].r)>>1; 89 if(k<=mid) 90 update(i<<1, k, val); 91 else 92 update(i<<1|1, k, val); 93 pushup(i); 94 } 95 int query(int i, int l, int r) 96 { 97 if(seg[i].l==l && seg[i].r==r) 98 return seg[i].Max; 99 int mid=(seg[i].l+seg[i].r)>>1; 100 if(r<=mid) 101 return query(i<<1, l, r); 102 else if(l>mid) 103 return query((i<<1)|1, l, r); 104 else 105 return max(query(i<<1, l, mid), query((i<<1)|1, mid+1, r)); 106 } 107 int find(int u, int v) 108 { 109 int f1=top[u], f2=top[v]; 110 int tmp=0; 111 while(f1!=f2) 112 { 113 if(deep[f1]<deep[f2]) 114 { 115 swap(f1, f2); 116 swap(u, v); 117 } 118 tmp=max(tmp, query(1, p[f1], p[u])); 119 u=fa[f1]; 120 f1=top[u]; 121 } 122 if(u==v) 123 return tmp; 124 if(deep[u]>deep[v]) 125 swap(u, v); 126 return max(tmp, query(1, p[son[u]], p[v])); 127 } 128 129 int e[MAXN][3]; 130 int main() 131 { 132 int T; 133 scanf("%d", &T); 134 while(T--) 135 { 136 init(); 137 int n; 138 scanf("%d", &n); 139 for(int i=0;i<n-1;i++) 140 { 141 scanf("%d%d%d", &e[i][0], &e[i][1], &e[i][2]); 142 addedge(e[i][0], e[i][1]); 143 addedge(e[i][1], e[i][0]); 144 } 145 dfs1(1, 0, 0); 146 getpos(1,1); 147 build(1, 0, pos-1); 148 for(int i=0;i<n-1;i++) 149 { 150 if(deep[e[i][0]]>deep[e[i][1]]) 151 swap(e[i][0], e[i][1]); 152 update(1, p[e[i][1]], e[i][2]); 153 } 154 char op[10]; 155 while(~scanf("%s", op)) 156 { 157 if(op[0]=='D') 158 break; 159 int u, v; 160 scanf("%d%d", &u, &v); 161 if(op[0]=='Q') 162 printf("%d ", find(u, v)); 163 else 164 update(1, p[e[u-1][1]], v); 165 } 166 } 167 return 0; 168 }
点权
树状数组
1 const int MAXN=50005; 2 struct Edge 3 { 4 int to, next; 5 }edge[MAXN<<1]; 6 int head[MAXN], tot; 7 int top[MAXN]; 8 int fa[MAXN]; 9 int deep[MAXN]; 10 int num[MAXN]; 11 int p[MAXN]; 12 int fp[MAXN]; 13 int son[MAXN]; 14 int pos; 15 void init() 16 { 17 tot=0; 18 memset(head, -1, sizeof(head)); 19 pos=1; 20 memset(son, -1, sizeof(son)); 21 } 22 void addedge(int u, int v) 23 { 24 edge[tot].to=v; 25 edge[tot].next=head[u]; 26 head[u]=tot++; 27 } 28 void dfs1(int u, int pre, int d) 29 { 30 deep[u]=d; 31 fa[u]=pre; 32 num[u]=1; 33 for(int i=head[u];i!=-1;i=edge[i].next) 34 { 35 int v=edge[i].to; 36 if(v!=pre) 37 { 38 dfs1(v, u, d+1); 39 num[u]+=num[v]; 40 if(son[u]==-1 || num[v]>num[son[u]]) 41 son[u]=v; 42 } 43 } 44 } 45 void getpos(int u, int sp) 46 { 47 top[u]=sp; 48 p[u]=pos++; 49 fp[p[u]]=u; 50 if(son[u]==-1) 51 return ; 52 getpos(son[u], sp); 53 for(int i=head[u];i!=-1;i=edge[i].next) 54 { 55 int v=edge[i].to; 56 if(v!=son[u] && v!=fa[u]) 57 getpos(v, v); 58 } 59 } 60 61 int lowbit(int x) 62 { 63 return x & (-x); 64 } 65 int c[MAXN]; 66 int n; 67 int sum(int i) 68 { 69 int s=0; 70 while(i>0) 71 { 72 s+=c[i]; 73 i-=lowbit(i); 74 } 75 return s; 76 } 77 void add(int i, int val) 78 { 79 while(i<=n) 80 { 81 c[i]+=val; 82 i+=lowbit(i); 83 } 84 } 85 void change(int u, int v, int val) 86 { 87 int f1=top[u], f2=top[v]; 88 while(f1!=f2) 89 { 90 if(deep[f1]<deep[f2]) 91 { 92 swap(f1, f2); 93 swap(u, v); 94 } 95 add(p[f1], val); 96 add(p[u]+1, -val); 97 u=fa[f1]; 98 f1=top[u]; 99 } 100 if(deep[u]>deep[v]) 101 swap(u, v); 102 add(p[u], val); 103 add(p[v]+1, -val); 104 } 105 106 int a[MAXN]; 107 int main() 108 { 109 int M, P; 110 while(~scanf("%d%d%d", &n, &M, &P)) 111 { 112 init(); 113 for(int i=1;i<=n;i++) 114 scanf("%d", &a[i]); 115 while(M--) 116 { 117 int u, v; 118 scanf("%d%d", &u, &v); 119 addedge(u, v); 120 addedge(v, u); 121 } 122 dfs1(1, 0, 0); 123 getpos(1,1); 124 memset(c, 0, sizeof(c)); 125 for(int i=1;i<=n;i++) 126 { 127 add(p[i], a[i]); 128 add(p[i]+1, -a[i]); 129 } 130 while(P--) 131 { 132 char op[10]; 133 scanf("%s", op); 134 if(op[0]=='Q') 135 { 136 int x; 137 scanf("%d", &x); 138 printf("%d ", sum(p[x])); 139 } 140 else 141 { 142 int x, y, z; 143 scanf("%d%d%d", &x, &y, &z); 144 if(op[0]=='D') 145 z=-z; 146 change(x, y, z); 147 } 148 } 149 } 150 return 0; 151 }