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| #include<stdio.h> #include<string.h> #include<algorithm> #define N 10005 #define inf 0x3f3f3f3f using namespace std; struct node { int u,v,w,next; }edge[N<<1]; int T,n,a,b,c; char op[10]; int pre[N],cnt; int son[N],dep[N],tid[N]; int top[N],fa[N],siz[N],id; int maxx[N<<2]; int e[N][3]; void init() { cnt = id = 0; memset(pre, -1, sizeof(pre)); memset(maxx, -inf, sizeof(maxx)); memset(siz, 0, sizeof(siz)); } void addEdge(int u, int v, int w) { edge[cnt].u = u; edge[cnt].v = v; edge[cnt].next = pre[u]; pre[u] = cnt++; } void dfs1(int u, int f, int dp) { dep[u] = dp; fa[u] = f; siz[u] = 1; son[u] = 0; 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] == 0)return ; dfs2(son[u], tp); for(int i = pre[u]; ~i; i=edge[i].next) { int v = edge[i].v; if(v != son[u] && v != fa[u]) dfs2(v, v); } } void update(int rt, int l, int r, int pos, int w) { if(l == r && l == pos) { maxx[rt] = w; return ; } int mid = (l + r) >> 1; if(pos <= mid) update(rt<<1, l, mid, pos, w); else update(rt<<1|1, mid+1, r, pos, w); maxx[rt] = max(maxx[rt<<1], maxx[rt<<1|1]); } int query(int rt, int l, int r, int ql, int qr) { if(ql <= l && r <= qr) return maxx[rt]; int mid = (l + r) >> 1; 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 get(int x, int y) { int ans = -inf; while(top[x] != top[y]) { if(dep[top[x]] < dep[top[y]]) swap(x, y); ans = max(ans, query(1, 2, n, tid[top[x]], tid[x])); x = fa[top[x]]; } if(x != y) { if(dep[x] > dep[y]) swap(x, y); ans = max(ans, query(1, 2, n, tid[x]+1, tid[y])); } return ans; } 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, 2, n, tid[e[i][1]], e[i][2]); } } int main() { scanf("%d", &T); while(T--) { init(); scanf("%d", &n); for(int i = 1; i < n; ++i) { scanf("%d%d%d", &a,&b,&c); addEdge(a, b, c); addEdge(b, a, c); e[i][0] = a,e[i][1] = b,e[i][2] = c; } deal(); while(~scanf("%s", op) && op[0]!='D') { scanf("%d%d", &a,&b); if(op[0] == 'Q') printf("%d\n", get(a, b)); else update(1, 2, n, tid[e[a][1]], b); } } return 0; }
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