Create boxes.cpp

Changes

1 changed files (+75/-0)

• 2019/US Open/Platinum/boxes.cpp (new)
  • @@ -0,0 +1,75 @@
    + #include <bits/stdc++.h> + #include "grader.h" + using namespace std; + typedef pair<int, int> ii; + typedef vector<int> vi; + typedef vector<ii> vii; + + int d[100005], sz[100005], L[100005][20]; + ii P[100005]; + vi G[100005]; + + void addRoad(int a, int b) { + G[a].push_back(b); + G[b].push_back(a); + } + + void dfs(int u, int p) { + d[u] = (p != -1 ? d[p] : 0) + 1; + sz[u] = 1; + L[u][0] = p; + for (int i = 0; i < 16; i++) { + if (L[u][i] != -1) L[u][i + 1] = L[L[u][i]][i]; + } + for (auto& v : G[u]) { + if (v != p) { + dfs(v, u); + sz[u] += sz[v]; + } + } + } + + int lca(int u, int v) { + if (d[u] > d[v]) swap(u, v); + for (int i = 16; i >= 0; i--) if (d[v] - (1 << i) >= d[u]) v = L[v][i]; + if (u == v) return u; + for (int i = 16; i >= 0; i--) if (L[u][i] != -1 && L[u][i] != L[v][i]) u = L[u][i], v = L[v][i]; + return L[u][0]; + } + + int pre(int l, int u) { + for (int i = 16; i >= 0; i--) { + if (L[u][i] != -1 && d[L[u][i]] > d[l]) u = L[u][i]; + } + return u; + } + + void solve(int u, int p, int x, int y) { + P[u] = ii(x, y); + setFarmLocation(u, x, y); + y += sz[u]; + for (auto& v : G[u]) { + if (v != p) { + y -= sz[v]; + solve(v, u, x, y); + x += sz[v]; + } + } + } + + void buildFarms() { + memset(L, -1, sizeof(L)); + dfs(0, -1); + solve(0, -1, 1, 1); + } + + void notifyFJ(int a, int b) { + if (a == b) addBox(P[a].first, P[a].second, P[a].first, P[a].second); + else { + int u = lca(a, b); + int v = pre(u, (a != u ? a : b)); + if (a != u) swap(u, v); + addBox(P[u].first, P[u].second, P[a].first, P[a].second); + addBox(P[v].first, P[v].second, P[b].first, P[b].second); + } + }