Submission #894131

#TimeUsernameProblemLanguageResultExecution timeMemory
894131vovikCats or Dogs (JOI18_catdog)C++17
100 / 100
127 ms27480 KiB
#include <bits/stdc++.h> void initialize(int N, std::vector<int> A, std::vector<int> B); int cat(int v); int dog(int v); int neighbor(int v); struct segTree { int n; using node = std::array<std::array<int, 2>, 2>; std::vector<node> t; node merge(node a, node b) { node c; for (int i = 0; i < 2; ++i) for (int j = 0; j < 2; ++j) c[i][j] = std::min({a[i][0] + b[0][j], a[i][1] + b[1][j]}); return c; } segTree() = default; segTree(int n) { while (__builtin_popcount(n) != 1) ++n; this->n = n, t = std::vector<node>(n * 2); for (auto&f: t) f[0][1] = f[1][0] = 1; } void modify(int i, int x, int y) { i += n; t[i][0][0] += x, t[i][0][1] += x; t[i][1][0] += y, t[i][1][1] += y; while (i /= 2) t[i] = merge(t[i * 2], t[i * 2 + 1]); } std::pair<int, int> get() { int x = std::min(t[1][0][0], t[1][0][1]); int y = std::min(t[1][1][0], t[1][1][1]); return {std::min(x, y + 1), std::min(x + 1, y)}; } }; segTree ok[100005]; int pos[100005], p[100005], f[100005], sz[100005], len[100005], tp[100005]; std::vector<int> g[100005]; void cfs(int v = 1, int p = -1) { for (int i = 0; i < g[v].size(); ++i) if (g[v][i] == p) g[v].erase(g[v].begin() + i); sz[v] = 1; for (auto u: g[v]) if (u != p) cfs(u, v), sz[v] += sz[u], ::p[u] = v; std::sort(g[v].begin(), g[v].end(), [](const int&v, const int&u) { return sz[v] > sz[u]; }); } void dfs(int v = 1, int s = 1) { f[v] = s, pos[v] = len[s]++; for (auto u: g[v]) dfs(u, u == g[v].front() ? s : u); } void initialize(int N, std::vector<int> A, std::vector<int> B) { for (int i = 0; i < A.size(); ++i) g[A[i]].push_back(B[i]), g[B[i]].push_back(A[i]); cfs(), dfs(); for (int v = 1; v <= N; ++v) if (!pos[v]) ok[v] = len[v]; } void modify(int v, int x, int y) { while (v) { auto [w0, w1] = ok[f[v]].get(); ok[f[v]].modify(pos[v], x, y); auto [n0, n1] = ok[f[v]].get(); x = n0 - w0, y = n1 - w1, v = p[f[v]]; } } int query() { auto [a, b] = ok[1].get(); return std::min(a, b); } int cat(int v) { return tp[v] = 1, modify(v, 1e9, 0), query(); } int dog(int v) { return tp[v] = 2, modify(v, 0, 1e9), query(); } int neighbor(int v) { return modify(v, -1e9 * (tp[v] == 1), -1e9 * (tp[v] == 2)), tp[v] = 0, query(); } #ifdef __APPLE__ #include <cstdio> #include <cassert> #include <vector> #include <cstdlib> int readInt() { int i; if (scanf("%d", &i) != 1) { fprintf(stderr, "Error while reading input\n"); exit(1); } return i; } int main() { int N = readInt(); std::vector<int> A(N - 1), B(N - 1); for (int i = 0; i < N - 1; i++) { A[i] = readInt(); B[i] = readInt(); } int Q; assert(scanf("%d",&Q)==1); std::vector<int> T(Q), V(Q); for (int i = 0; i < Q; i++) { T[i] = readInt(); V[i] = readInt(); } initialize(N, A, B); std::vector<int> res(Q); for (int j = 0; j < Q; j++) { if (T[j] == 1) res[j] = cat(V[j]); else if (T[j] == 2) res[j] = dog(V[j]); else res[j] = neighbor(V[j]); } for (int j = 0; j < Q; j++) printf("%d\n", res[j]); return 0; } #endif

Compilation message (stderr)

catdog.cpp: In function 'void cfs(int, int)':
catdog.cpp:51:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for (int i = 0; i < g[v].size(); ++i) if (g[v][i] == p) g[v].erase(g[v].begin() + i);
      |                     ~~^~~~~~~~~~~~~
catdog.cpp: In function 'void initialize(int, std::vector<int>, std::vector<int>)':
catdog.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for (int i = 0; i < A.size(); ++i) g[A[i]].push_back(B[i]), g[B[i]].push_back(A[i]);
      |                     ~~^~~~~~~~~~
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