File size: 4,264 Bytes
1fd0050 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | #include <iostream>
#include <vector>
#include <numeric>
#include <algorithm>
using namespace std;
const int MAXN = 1005;
vector<pair<int, int>> adj[MAXN];
int p[MAXN];
int n;
int parent[MAXN];
int depth[MAXN];
int tin[MAXN], tout[MAXN];
int timer;
vector<int> nodes_at_depth[MAXN];
int max_depth;
struct Edge {
int u, v, id;
};
vector<Edge> edges;
int edge_map[MAXN][MAXN];
void dfs(int v, int p, int d) {
tin[v] = ++timer;
parent[v] = p;
depth[v] = d;
if (d > max_depth) max_depth = d;
nodes_at_depth[d].push_back(v);
for (auto& edge_pair : adj[v]) {
int to = edge_pair.first;
if (to != p) {
dfs(to, v, d + 1);
}
}
tout[v] = ++timer;
}
bool is_in_subtree(int u, int v) {
if (v == 0) return true;
if (u == 0) return false;
return tin[v] <= tin[u] && tout[u] <= tout[v];
}
void apply_operation(const vector<int>& op) {
vector<pair<int,int>> to_swap;
for (int edge_id : op) {
to_swap.push_back({edges[edge_id - 1].u, edges[edge_id - 1].v});
}
for(auto swp : to_swap){
swap(p[swp.first], p[swp.second]);
}
}
void solve() {
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> p[i];
adj[i].clear();
nodes_at_depth[i-1].clear();
}
nodes_at_depth[n].clear();
edges.clear();
for (int i = 0; i < n - 1; ++i) {
int u, v;
cin >> u >> v;
adj[u].push_back({v, i + 1});
adj[v].push_back({u, i + 1});
edges.push_back({u, v, i + 1});
edge_map[u][v] = edge_map[v][u] = i+1;
}
timer = 0;
max_depth = 0;
dfs(1, 0, 0);
vector<vector<int>> operations;
while (true) {
bool changed = false;
// Bottom-up phase
for (int d = max_depth; d >= 1; --d) {
vector<int> current_op;
vector<bool> matched(n + 1, false);
for (int u : nodes_at_depth[d]) {
int target = p[u];
if (!is_in_subtree(target, u)) {
int par = parent[u];
if (par != 0 && !matched[u] && !matched[par]) {
current_op.push_back(edge_map[u][par]);
matched[u] = true;
matched[par] = true;
}
}
}
if (!current_op.empty()) {
operations.push_back(current_op);
apply_operation(current_op);
changed = true;
}
}
if (!changed) break;
}
while (true) {
bool sorted = true;
for(int i = 1; i <= n; ++i) if(p[i] != i) sorted = false;
if(sorted) break;
bool changed = false;
// Top-down phase
for (int d = 0; d < max_depth; ++d) {
vector<int> current_op;
vector<bool> matched(n + 1, false);
for (int u : nodes_at_depth[d]) {
if (p[u] != u) {
int target = p[u];
int child_on_path = 0;
for(auto& edge_pair : adj[u]){
int to = edge_pair.first;
if(parent[to] == u && is_in_subtree(target, to)){
child_on_path = to;
break;
}
}
if(child_on_path != 0 && !matched[u] && !matched[child_on_path]){
current_op.push_back(edge_map[u][child_on_path]);
matched[u] = true;
matched[child_on_path] = true;
}
}
}
if (!current_op.empty()) {
operations.push_back(current_op);
apply_operation(current_op);
changed = true;
}
}
if(!changed) break;
}
cout << operations.size() << endl;
for (const auto& op : operations) {
cout << op.size();
for (int edge_id : op) {
cout << " " << edge_id;
}
cout << endl;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t;
cin >> t;
while (t--) {
solve();
}
return 0;
} |