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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
#318268#5017. 相等树链yllcm0 832ms76228kbC++143.8kb2024-01-30 21:27:312024-01-30 21:27:31

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你现在查看的是最新测评结果

  • [2024-01-30 21:27:31]
  • 评测
  • 测评结果:0
  • 用时:832ms
  • 内存:76228kb
  • [2024-01-30 21:27:31]
  • 提交

answer

#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pb push_back
#define pii pair<int, int>
#define FR first
#define SE second
using namespace std;
inline int read() {
  int x = 0; bool op = 0;
  char c = getchar();
  while(!isdigit(c))op |= (c == '-'), c = getchar();
  while(isdigit(c))x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
  return op ? -x : x;
}
const int N = 2e5 + 10;
int n, S, tim;
ll ans;
ull val[N];
mt19937_64 rnd(114514);
vector<int> G1[N], G2[N];
int nxt[N], vis[N], id[N];
unordered_map<ull, int> cnt;
struct Node {int x, y;};
int st[N][25], dep[N], dfn[N];
void dfs(int u, int fa) {
  st[dfn[u] = ++tim][0] = fa; dep[u] = dep[fa] + 1;
  for(int v : G1[u])if(v != fa)dfs(v, u);
  return ;
}
int cmin(int x, int y) {return dep[x] < dep[y] ? x : y;}
void build() {
  for(int j = 1; (1 << j) <= n; j++) {
    for(int i = 1; i + (1 << j) - 1 <= n; i++) {
      st[i][j] = cmin(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
    }
  }
  return ;
}
int lca(int u, int v) {
  if(u == v)return u;
  int l = dfn[u], r = dfn[v];
  if(l > r)swap(l, r);
  int t = __lg(r - (l++));
  return cmin(st[l][t], st[r - (1 << t) + 1][t]);
}
int dist(int u, int v) {return dep[u] + dep[v] - 2 * dep[lca(u, v)];}
Node merge(Node x, int u) {
  if(!~x.x && !~x.y)return (Node){-1, -1};
  Node now = x;
  if(dist(x.x, u) > dist(now.x, now.y))now = (Node){x.x, u};
  if(dist(x.y, u) > dist(now.x, now.y))now = (Node){x.y, u};
  vector<int> p = {x.x, x.y, u};
  auto chk = [&](Node x, int u) {return dist(x.x, u) + dist(x.y, u) == dist(x.x, x.y);};
  for(int x : p)if(!chk(now, x))return (Node){-1, -1};
  return now;
}
void dfs2(int u, int fa, ull now, Node p, int op) {
  now ^= val[u]; now ^= val[nxt[u]];
  p = merge(p, u);
  if(~p.x && ~p.y) {
    if(!op) {
      ans += cnt[now];
      ans += cnt[now ^ val[p.x]];
      if(p.x != p.y) {
        ans += cnt[now ^ val[p.y]];
        ans += cnt[now ^ val[p.x] ^ val[p.y]];
      }
      // printf("qwq:%d %d %d %d\n", u, p.x, p.y, ans);
    }
    else {
      cnt[now]++;
      cnt[now ^ val[p.x]]++;
      cnt[now ^ val[p.y]]++;
      cnt[now ^ val[p.x] ^ val[p.y]]++;
    }
  }
  for(int v : G2[u])if(v != fa && id[v] == tim)dfs2(v, u, now, p, op);
  return ;
}
void calc(int u) {
  unordered_map<ull, int>().swap(cnt);
  cnt[0] = cnt[val[u]] = 1;
  for(int v : G2[u]) {
    if(id[v] != tim)continue;
    dfs2(v, u, 0, (Node){v, v}, 0); 
    dfs2(v, u, 0, (Node){v, v}, 1);
    return ;
  }
  return ;
}
int root;
int sz[N];
void findroot(int u, int fa) {
  int mx = 0; sz[u] = 1;
  for(int v : G1[u]) {
    if(v == fa || vis[v])continue;
    findroot(v, u); sz[u] += sz[v];
    mx = max(mx, sz[v]);
  }
  if(max(S - sz[u], mx) * 2 <= S)root = u;
  return ;
}
void dfs1(int u, int fa) {
  id[u] = tim; nxt[u] = fa;
  for(int v : G1[u]) {
    if(v == fa || vis[v])continue;
    dfs1(v, u);
  }
  return ;
}
void solve(int u) {
  // if(S > 0)cerr << u << ' ' << S << endl;
  // cerr << "solve:" << u << ' ' << root << ' ' << vis[root] << ' ' << S << endl;
  findroot(u, 0); u = root;
  tim++; dfs1(u, 0); calc(u);
  vis[u] = true;
  // printf("%d %d\n", u, ans);
  int nS = S;
  for(int v : G1[u]) {
    if(vis[v])continue;
    S = sz[v] > sz[u] ? nS - sz[u] : sz[v];
    // cerr << u << ' ' << v << endl;
    solve(v);
  }
  return ;
}
int main() { 
  n = read();
  for(int i = 1; i <= n; i++)val[i] = rnd();
  for(int i = 2; i <= n; i++) {
    int u = read();
    G1[u].pb(i); G1[i].pb(u);
  }
  for(int i = 2; i <= n; i++) {
    int u = read();
    // printf("%d %d\n", u, i);
    G2[u].pb(i); G2[i].pb(u);
  }
  dfs(1, 0); build();
  S = ans = n; solve(1);
  printf("%lld\n", ans);
  return 0;
}

详细

Subtask #1:

score: 0
Wrong Answer

Test #1:

score: 0
Wrong Answer
time: 9ms
memory: 18752kb

input:

5000
1296 1400 867 4533 1296 2007 2059 115 821 2960 3187 1597 2409 2708 4743 4778 1345 3967 911 3400 4249 3793 339 3145 3490 607 4148 3513 3264 3852 568 775 828 1348 423 3678 305 1938 1096 1373 2662 1048 4328 4208 203 779 3103 3372 4523 192 264 792 4943 2211 2494 3513 3555 4935 3277 3390 4624 128 18...

output:

7471

result:

wrong answer 1st numbers differ - expected: '76002', found: '7471'

Subtask #2:

score: 0
Wrong Answer

Test #6:

score: 0
Wrong Answer
time: 832ms
memory: 76228kb

input:

200000
13177 40498 104798 83659 186055 32788 86489 72123 13521 134868 158968 60124 166316 163390 120935 103000 83938 57807 97940 40447 137723 154683 191864 59080 102808 3969 21451 165592 128776 49468 4101 26441 139317 59503 18053 118809 187783 149816 21609 98521 165692 52964 60425 23437 29614 106886...

output:

356268

result:

wrong answer 1st numbers differ - expected: '5859368', found: '356268'

Subtask #3:

score: 0
Skipped

Dependency #2:

0%

Subtask #4:

score: 0
Skipped

Dependency #1:

0%