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| #include<stdio.h> #include<algorithm> #include<string.h> #define N 100005 #define inf 0x3f3f3f3f using namespace std; struct node { int v,next; } edge[N<<2]; int e[N][3]; int son[N],dep[N],fa[N]; int id,tid[N],top[N],siz[N]; int cnt,pre[N]; int Max[N<<2],Min[N<<2],add[N<<2]; int T,n,a,b,c; char op[5]; int Scan() { int flag = 1,res = 0; char ch; while((ch = getchar()) == ' ' || ch == '\n'); if(ch == '-') flag = -1; else res = ch - '0'; while((ch = getchar()) != ' ' && ch != '\n') res = res * 10 + ch - '0'; return flag * res; } void init() { cnt = id = 0; memset(pre, -1, sizeof(pre)); memset(son, 0, sizeof(son)); memset(siz, 0, sizeof(siz)); memset(Max, -inf, sizeof(Max)); memset(Min, inf, sizeof(Min)); memset(add, 0, sizeof(add)); } void addEdge(int u, int v) { edge[cnt].v = v; edge[cnt].next = pre[u]; pre[u] = cnt++; } void dfs1(int u, int f, int dp) { fa[u] = f,dep[u] = dp,son[u] = 0,siz[u] = 1; for(int i = pre[u]; ~i; i=edge[i].next) { int v = edge[i].v; if(v != f) { dfs1(v, u, dp+1); siz[u] += siz[v]; if(siz[v] > siz[son[u]]) son[u] = v; } } } void dfs2(int u, int tp) { top[u] = tp,tid[u] = ++id; if(son[u]) dfs2(son[u], tp); for(int i = pre[u]; ~i; i=edge[i].next) { int v = edge[i].v; if(v != fa[u] && v != son[u]) dfs2(v, v); } } void push_up(int rt) { Max[rt] = max(Max[rt<<1], Max[rt<<1|1]); Min[rt] = min(Min[rt<<1], Min[rt<<1|1]); } void push_down(int rt) { if(add[rt]) { add[rt<<1] = (add[rt<<1] + 1) % 2; add[rt<<1|1] = (add[rt<<1|1] + 1) % 2; add[rt] = 0; int maxl = Max[rt<<1],maxr = Max[rt<<1|1]; Max[rt<<1] = -Min[rt<<1]; Min[rt<<1] = -maxl; Max[rt<<1|1] = -Min[rt<<1|1]; Min[rt<<1|1] = -maxr; push_up(rt); } } void update_1(int rt, int l, int r, int pos, int v) { if(l == r && l == pos) { add[rt] = 0; Max[rt] = Min[rt] = v; return ; } push_down(rt); int mid = (l + r) >> 1; if(pos <= mid) update_1(rt<<1, l, mid, pos, v); else update_1(rt<<1|1, mid+1, r, pos, v); push_up(rt); } void deal() { dfs1(1, 1, 1); dfs2(1, 1); for(int i = 1; i < n; ++i) { if(dep[e[i][0]] > dep[e[i][1]]) swap(e[i][0], e[i][1]); update_1(1, 2, n, tid[e[i][1]], e[i][2]); } } void update_2(int rt, int l, int r, int ql, int qr) { if(ql <= l && r <= qr) { add[rt] = (add[rt] + 1) % 2; int mmax = Max[rt]; Max[rt] = -Min[rt],Min[rt] = -mmax; return ; } int mid = (l + r) >> 1; push_down(rt); if(ql <= mid) update_2(rt<<1, l, mid, ql, qr); if(qr > mid) update_2(rt<<1|1, mid+1, r, ql, qr); push_up(rt); } void lca_up(int u, int v) { while(top[u] != top[v]) { if(dep[top[u]] < dep[top[v]]) swap(u, v); update_2(1, 2, n, tid[top[u]], tid[u]); u = fa[top[u]]; } if(u != v) { if(dep[u] > dep[v]) swap(u, v); update_2(1, 2, n, tid[u]+1, tid[v]); } } int query(int rt, int l, int r, int ql, int qr) { if(ql <= l && r <= qr) return Max[rt]; int mid = (l + r) >> 1; push_down(rt); if(qr <= mid) return query(rt<<1, l, mid, ql, qr); if(ql > mid) return query(rt<<1|1, mid+1, r, ql, qr); return max(query(rt<<1, l, mid, ql, qr), query(rt<<1|1, mid+1, r, ql, qr)); } int lca_query(int u, int v) { int ans = -inf; while(top[u] != top[v]) { if(dep[top[u]] < dep[top[v]]) swap(u, v); ans = max(ans, query(1, 2, n, tid[top[u]], tid[u])); u = fa[top[u]]; } if(u != v) { if(dep[u] > dep[v]) swap(u, v); ans = max(ans, query(1, 2, n, tid[u]+1, tid[v])); } return ans; } int main() { T = Scan(); while(T--) { init(); n = Scan(); for(int i = 1; i < n; ++i) { e[i][0] = Scan(),e[i][1] = Scan(),e[i][2] = Scan(); addEdge(e[i][0], e[i][1]); addEdge(e[i][1], e[i][0]); } deal(); while(~scanf("%s", op) && op[0] != 'D') { a = Scan(),b = Scan(); if(op[0] == 'C') update_1(1, 2, n, tid[e[a][1]], b); else if(op[0] == 'N') lca_up(a, b); else printf("%d\n", lca_query(a, b)); } } return 0; }
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