1 #include<cstdio> 2 #include<cstring> 3 #include<queue> 4 #include<iostream> 5 #include<algorithm> 6 #define MAXN 100010 7 #define MAXM 200010 8 using namespace std; 9 bool vis[MAXN]; 10 int first[MAXN], second[MAXM], v[MAXM], e; 11 struct LCT { 12 int bef[MAXN]; 13 int next[MAXN][2], pre[MAXN], key[MAXN], val[MAXN]; 14 void Init() { 15 memset(next, 0, sizeof(next)); 16 memset(pre, 0, sizeof(pre)); 17 memset(key, 0, sizeof(key)); 18 } 19 inline void PushUp(int x) { 20 val[x] = max(key[x], max(val[next[x][0]], val[next[x][1]])); 21 } 22 inline void Rotate(int x, int kind) { 23 int y, z; 24 y = pre[x]; 25 z = pre[y]; 26 next[y][!kind] = next[x][kind]; 27 pre[next[x][kind]] = y; 28 next[z][next[z][1] == y] = x; 29 pre[x] = z; 30 next[x][kind] = y; 31 pre[y] = x; 32 PushUp(y); 33 } 34 void Splay(int x) { 35 int rt; 36 for (rt = x; pre[rt]; rt = pre[rt]) 37 ; 38 if (rt != x) { 39 bef[x] = bef[rt]; 40 bef[rt] = 0; 41 while (pre[x]) { 42 if (next[pre[x]][0] == x) 43 Rotate(x, 1); 44 else 45 Rotate(x, 0); 46 } 47 PushUp(x); 48 } 49 } 50 void Access(int x) { 51 int father; 52 for (father = 0; x; x = bef[x]) { 53 Splay(x); 54 bef[next[x][1]] = x; 55 pre[next[x][1]] = 0; 56 next[x][1] = father; 57 pre[father] = x; 58 bef[father] = 0; 59 father = x; 60 PushUp(x); 61 } 62 } 63 void Change(int x, int val) { 64 key[x] += val; 65 Splay(x); 66 } 67 int Query(int x, int y) { 68 Access(y); 69 for (y = 0; x; x = bef[x]) { 70 Splay(x); 71 if (!bef[x]) 72 return max(key[x], max(val[next[x][1]], val[y])); 73 bef[next[x][1]] = x; 74 pre[next[x][1]] = 0; 75 next[x][1] = y; 76 pre[y] = x; 77 bef[y] = 0; 78 y = x; 79 PushUp(x); 80 } 81 return 0; 82 } 83 } lct; 84 int INT() { 85 int res; 86 char ch; 87 while (ch = getchar(), !isdigit(ch)) 88 ; 89 for (res = ch - '0'; ch = getchar(), isdigit(ch);) 90 res = res * 10 + ch - '0'; 91 return res; 92 } 93 char CHAR() { 94 char res; 95 while (res = getchar(), !isalpha(res)) 96 ; 97 return res; 98 } 99 inline void AddEdge(int x, int y) { 100 v[e] = y; 101 second[e] = first[x]; 102 first[x] = e++; 103 } 104 void BFS(int x) { 105 int i, y; 106 queue<int> q; 107 memset(vis, false, sizeof(vis)); 108 vis[x] = true; 109 q.push(x); 110 while (!q.empty()) { 111 x = q.front(); 112 q.pop(); 113 for (i = first[x]; i != -1; i = second[i]) { 114 y = v[i]; 115 if (!vis[y]) { 116 lct.bef[y] = x; 117 vis[y] = true; 118 q.push(y); 119 } 120 } 121 } 122 } 123 int main() { 124 char ch; 125 int n, i, q, x, y; 126 while (~scanf("%d", &n)) { 127 lct.Init(); 128 memset(first, -1, sizeof(first)); 129 for (e = 0, i = 1; i < n; i++) { 130 x = INT(), y = INT(); 131 AddEdge(x, y); 132 AddEdge(y, x); 133 } 134 BFS(1); 135 q = INT(); 136 while (q--) { 137 ch = CHAR(), x = INT(), y = INT(); 138 if (ch == 'I') 139 lct.Change(x, y); 140 else 141 printf("%d\n", lct.Query(x, y)); 142 } 143 } 144 return 0; 145 }
