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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#417828#8716. 树wsyearWA 0ms11116kbC++171.8kb2024-05-22 22:58:192024-05-22 22:58:20

Judging History

你现在查看的是最新测评结果

  • [2024-05-22 22:58:20]
  • 评测
  • 测评结果:WA
  • 用时:0ms
  • 内存:11116kb
  • [2024-05-22 22:58:19]
  • 提交

answer

#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 200010;

int n, m, q, fa[maxn][20], dep[maxn], a[maxn];
vector<int> e[maxn];

void dfs(int u, int f) {
  fa[u][0] = f, dep[u] = dep[f] + 1;
  for (int v : e[u]) if (v != f) dfs(v, u);
}

int lca(int u, int v) {
  if (dep[u] < dep[v]) swap(u, v);
  int dc = dep[u] - dep[v];
  per (i, 19, 0) if (dc >> i & 1) u = fa[u][i];
  if (u == v) return u;
  per (i, 19, 0) if (fa[u][i] == fa[v][i]) u = fa[u][i], v = fa[v][i];
  return fa[u][0];
}

int dis(int u, int v) {
  return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}

int check(int x, int y, int z) {
  return dis(x, z) == dis(x, y) + dis(y, z);
}

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n >> m >> q;
  rep (i, 1, n - 1) {
    int u, v;
    cin >> u >> v;
    e[u].emplace_back(v);
    e[v].emplace_back(u);
  }
  rep (i, 1, m) cin >> a[i];
  dfs(1, 0);
  rep (j, 1, 19) rep (i, 1, n) fa[i][j] = fa[fa[i][j - 1]][j - 1];
  int ans = 0;
  rep (i, 2, m - 1) if (check(a[i - 1], a[i], a[i + 1])) ans++;
  while (q--) {
    int x, y;
    cin >> x >> y;
    rep (i, max(2, x - 1), min(m - 1, x + 1)) if (check(a[i - 1], a[i], a[i + 1])) ans--;
    a[x] = y;
    rep (i, max(2, x - 1), min(m - 1, x + 1)) if (check(a[i - 1], a[i], a[i + 1])) ans++;
    cout << m - ans << '\n';
  }
}

詳細信息

Test #1:

score: 100
Accepted
time: 0ms
memory: 11116kb

input:

5 5 3
2 1
3 2
1 4
5 1
1 5 4 2 3
1 3
5 3
3 3

output:

4
4
5

result:

ok 3 number(s): "4 4 5"

Test #2:

score: -100
Wrong Answer
time: 0ms
memory: 10984kb

input:

30 200 200
10 24
10 13
10 26
13 29
27 26
17 24
27 21
17 15
13 5
13 30
27 3
18 21
9 21
2 24
10 4
11 5
2 8
10 23
1 18
21 25
4 20
12 23
22 27
28 27
18 7
13 6
14 30
10 19
16 21
14 29 25 30 1 17 22 21 11 19 21 30 13 1 22 10 14 7 29 7 15 21 25 29 25 7 29 7 1 23 3 17 2 7 4 27 18 26 3 6 5 3 16 26 20 19 16 2...

output:

180
181
181
181
181
181
181
181
182
182
183
183
182
182
182
182
181
181
181
181
180
179
179
179
179
179
179
180
180
180
180
179
178
179
179
179
179
179
179
179
179
179
178
178
178
179
178
178
178
177
178
179
179
179
179
179
179
179
179
179
179
180
179
179
179
179
179
180
180
181
181
181
181
181
180
...

result:

wrong answer 1st numbers differ - expected: '174', found: '180'