Submission #1056767

#	Time	Username	Problem	Language	Result	Execution time	Memory
1056767		vjudge1	Swapping Cities (APIO20_swap)	C++17	0 / 100	668 ms	524288 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
//#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<    
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>
const int MOD = 1e9+7,inf = 2e9;
const int L = 2e5+1;

struct DSU {
  int n;
  vi dad,change,sz;
  DSU(){};
  DSU(int nn) {
    n = nn;
    dad.resize(n),change.assign(n,0),sz.assign(n,1);
    iota(dad.begin(),dad.end(),0ll);
  }

  int find(int x,int t) {
    if (!change[x] || change[x] > t) return x;
    return find(dad[x],t);
  }
  void unite(int x,int y,int t) {
    int a = find(x,t);
    int b = find(y,t);
    if (a == b) return;
    if (sz[a] < sz[b]) swap(a,b);
    dad[b] = a;
    sz[a]+=sz[b];
    change[b] = t;
  }
};

vi vv;

int idx(int xx) {
  return upper_bound(all(vv),xx)-vv.begin();
}

struct Node{
  int v;
  Node *l,*r;
  Node() {
    l = r = NULL;
    v = 0;
  }
  Node(int x) {
    v = x;
    l = r = NULL;
  }
  Node(Node* cp) {
    l = cp->l,r = cp->r,v = cp->v;
  }
  Node(Node* L,Node* R,int V = 0) {
    l = L;
    r = R;
    v = V;
  }
};

Node* build(int l,int r) {
  if (l == r) return new Node;
  int m = (l+r) >> 1;
  return new Node(build(l,m),build(m+1,r));
}

Node* update(Node* node,int l,int r,int L,int R,int v) {
  if (l >= L && r <= R) return new Node(node->l,node->r,node->v+v);
  int m = (l+r) >> 1;
  if (m >= L && m+1 <= R) return new Node(update(node->l,l,m,L,R,v),update(node->r,m+1,r,L,R,v),node->v);
  if (m >= L) return new Node(update(node->l,l,m,L,R,v),node->r,node->v);
  return new Node(node->l,update(node->r,m+1,r,L,R,v),node->v);
}

int query(Node* node,int l,int r,int p) {
  if (l == r) return node->v;
  int m = (l+r) >> 1;
  if (p<=m) return node->v+query(node->l,l,m,p);
  return node->v+query(node->r,m+1,r,p);
}


map<int,int> realy;
Node* roots[L];
vi change(L,inf),tin(L),tout(L),par(L),egdes[L];
int timer = 1;
DSU dsu;

int up[L][20];

void dfs(int node,int p) {
  par[node] = up[node][0] = p;
  tin[node] = timer++;
  for (auto it : egdes[node]) if (it != p) dfs(it,node);
  tout[node] = timer-1;
}
bool anc(int x,int y) {
  return tin[x] <= tin[y] && tout[x] >= tout[y];
}

int lca(int a,int b) {
  if (anc(a,b)) return a;
  if (anc(b,a)) return b;
  for (int i=19;i>=0;i--) {
    if (!anc(up[a][i],b)) a = up[a][i];
  }
  return up[a][0];
}



int nn;
void init(int N, int M,
          std::vector<int> U, std::vector<int> V, std::vector<int> W) {
    nn = N;
    for (int i=0;i<M;i++) vv.push_back(W[i]);
    sort(all(vv));
    vv.erase(unique(all(vv)),vv.end());
    int cc = 1;
    for (auto it : vv) realy[cc++] = it; 
    for (int i=0;i<M;i++) {
      egdes[U[i]].push_back(V[i]);
      egdes[V[i]].push_back(U[i]);
    }
    dfs(0,0);
    for (int i=1;i<20;i++) {
      for (int j=0;j<N;j++) up[j][i] = up[up[j][i-1]][i-1];
    }
    if (M == N-1) {
      //tree case
      dsu = DSU(N);
      vector<pair<int,pii>> edges;
      for (int i=0;i<M;i++) edges.push_back({idx(W[i]),{U[i],V[i]}});
      sort(all(edges));
      for (auto it : edges) dsu.unite(it.ss.ff,it.ss.ss,it.ff);
      vi edg(N,0);
      int sz = vv.size();
      roots[0] = new Node;
      roots[0] = build(1,N);
      int ptr = 0;
      for (int i=1;i<=sz;i++) {
        roots[i] = roots[i-1];
        while (ptr < edges.size() && edges[ptr].ff == i) {
          edg[edges[ptr].ss.ff]++;
          edg[edges[ptr].ss.ss]++;
          if (edg[edges[ptr].ss.ff] == 3) {
            change[edges[ptr].ss.ff] = i;
            roots[i] = update(roots[i],1,N,tin[edges[ptr].ss.ff],tout[edges[ptr].ss.ff],1);
          }
          if (edg[edges[ptr].ss.ss] == 3) {
            change[edges[ptr].ss.ss] = i;
            roots[i] = update(roots[i],1,N,tin[edges[ptr].ss.ss],tout[edges[ptr].ss.ss],1);
          }
          ptr++;
        }
      }
      return;
    }
    assert(0);

}

int getMinimumFuelCapacity(int X, int Y) {
  int sz = vv.size();
  int l = 1;
  int r = sz;
  while (l<=r) {
    int m = (l+r) >> 1;
    if (dsu.find(X,m) != dsu.find(Y,m)) {
      l = m+1;
      continue;
    }
    if (!anc(X,Y) && !anc(Y,X)) {
      int a = query(roots[m],1,nn,tin[par[X]]);
      int b = query(roots[m],1,nn,tin[par[Y]]);
      int lc = lca(par[X],par[Y]);
      int c = query(roots[m],1,nn,tin[lc]);
      if (a+b-2*c+(change[lc]<=m)) r = m-1;
      else l = m+1;
      continue;
    }
    if (anc(Y,X)) swap(X,Y);
    if (X == par[Y]) {
      l = m+1;
      continue;
    }
    int bot = Y;
    for (int i=19;i>=0;i--) {
      if (!anc(up[bot][i],X)) bot = up[bot][i];
    }
    int a = query(roots[m],1,nn,tin[par[Y]]);
    int b = query(roots[m],1,nn,tin[bot]);
    if (a-b+(change[X]<=m)) r = m-1;
    else l = m+1;
  }
  if (l <= sz) return realy[l];
  return -1;
}

Compilation message (stderr)

swap.cpp: In function 'void init(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
swap.cpp:149:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  149 |         while (ptr < edges.size() && edges[ptr].ff == i) {
      |                ~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27