Submission #414504

#	Time	Username	Problem	Language	Result	Execution time	Memory
414504		mosiashvililuka	Highway Tolls (IOI18_highway)	C++14	51 / 100	220 ms	30580 KiB

highway

#include "highway.h"
#include<bits/stdc++.h>
using namespace std;
int a,b,c,d,e,i,j,ii,jj,zx,xc,A,B,msh[100009],dep[100009],lef,rig,mid,E,DEP,C,D;
long long K,KK,X;
vector <pair <int, int> > v[100009];
vector <int> vv,de[100009];
long long ask(const std::vector<int> &w);
void answer(int s, int t);
void dfs(int q, int w){
	dep[q]=dep[w]+1;
	de[dep[q]].push_back(q);
	DEP=max(DEP,dep[q]);
	for(vector <pair <int, int> >::iterator it=v[q].begin(); it!=v[q].end(); it++){
		if((*it).first==w) continue;
		msh[(*it).first]=(*it).second;
		dfs((*it).first,q);
	}
}
int fun(){
	lef=0;rig=de[E].size()-1;
	while(1){
		if(lef==rig) return de[E][lef];
		mid=(lef+rig)/2;
		for(i=0; i<b; i++){
			vv[i]=0;
		}
		for(i=lef; i<=mid; i++){
			vv[msh[de[E][i]]]=1;
		}
		X=ask(vv);
		if(K==X){
			lef=mid+1;
		}else{
			rig=mid;
		}
	}
}
void find_pair(int N, vector<int> U, vector<int> V, int AA, int BB) {
	A=AA;B=BB;
	a=N;b=U.size();
	for(i=0; i<U.size(); i++){
		U[i]++;
		V[i]++;
		v[U[i]].push_back(make_pair(V[i],i));
		v[V[i]].push_back(make_pair(U[i],i));
	}
	vv.resize(b);
	for(i=0; i<b; i++){
		vv[i]=0;
	}
	K=ask(vv);X=A;
	KK=K/X;
	DEP=0;
	dfs(1,0);
	lef=1;rig=DEP+1;
	while(1){
		if(lef+1>=rig) break;
		mid=(lef+rig)/2;
		for(i=1; i<=a; i++){
			if(i==1) continue;
			if(dep[i]>=mid){
				vv[msh[i]]=1;
			}else{
				vv[msh[i]]=0;
			}
		}
		X=ask(vv);
		if(K==X){
			rig=mid;
		}else{
			lef=mid;
		}
	}
	E=lef;
	C=fun();
	//answer(C-1,D-1);
	for(i=0; i<=a+1; i++){
		de[i].clear();
		dep[i]=0;msh[i]=0;
	}
	DEP=0;
	dfs(C,0);
	E=KK+1;
	D=fun();
	answer(C-1,D-1);
}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/*
namespace {
 
int MAX_NUM_CALLS = 100;
long long INF = 1LL << 61;
 
int N, M, A, B, S, T;
std::vector<int> U, V;
std::vector<std::vector<std::pair<int, int> > > graph;
 
bool answered, wrong_pair;
int num_calls;
 
int read_int() {
  int x;
  if (scanf("%d", &x) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  return x;
}
 
void wrong_answer(const char *MSG) {
  printf("Wrong Answer: %s\n", MSG);
  exit(0);
}
 
}  // namespace
 
long long ask(const std::vector<int> &w) {
  if (++num_calls > MAX_NUM_CALLS) {
    wrong_answer("more than 100 calls to ask");
  }
  if (w.size() != (size_t)M) {
    wrong_answer("w is invalid");
  }
  for (size_t i = 0; i < w.size(); ++i) {
    if (!(w[i] == 0 || w[i] == 1)) {
      wrong_answer("w is invalid");
    }
  }
 
  std::vector<bool> visited(N, false);
  std::vector<long long> current_dist(N, INF);
  std::queue<int> qa, qb;
  qa.push(S);
  current_dist[S] = 0;
  while (!qa.empty() || !qb.empty()) {
    int v;
    if (qb.empty() ||
        (!qa.empty() && current_dist[qa.front()] <= current_dist[qb.front()])) {
      v = qa.front();
      qa.pop();
    } else {
      v = qb.front();
      qb.pop();
    }
    if (visited[v]) {
      continue;
    }
    visited[v] = true;
    long long d = current_dist[v];
    if (v == T) {
      return d;
    }
    for (vector <pair <int, int> >::iterator ee=graph[v].begin(); ee!=graph[v].end(); ee++) {
      int vv = (*ee).first;
      int ei = (*ee).second;
      if (!visited[vv]) {
        if (w[ei] == 0) {
          if (current_dist[vv] > d + A) {
            current_dist[vv] = d + A;
            qa.push(vv);
          }
        } else {
          if (current_dist[vv] > d + B) {
            current_dist[vv] = d + B;
            qb.push(vv);
          }
        }
      }
    }
  }
  return -1;
}
 
void answer(int s, int t) {
  if (answered) {
    wrong_answer("answered not exactly once");
  }
 
  if (!((s == S && t == T) || (s == T && t == S))) {
    wrong_pair = true;
  }
 
  answered = true;
}
 
int main() {
  N = read_int();
  M = read_int();
  A = read_int();
  B = read_int();
  S = read_int();
  T = read_int();
  U.resize(M);
  V.resize(M);
  graph.assign(N, std::vector<std::pair<int, int>>());
  for (int i = 0; i < M; ++i) {
    U[i] = read_int();
    V[i] = read_int();
    graph[U[i]].push_back({V[i], i});
    graph[V[i]].push_back({U[i], i});
  }
 
  answered = false;
  wrong_pair = false;
  num_calls = 0;
  find_pair(N, U, V, A, B);
  if (!answered) {
    wrong_answer("answered not exactly once");
  }
  if (wrong_pair) {
    wrong_answer("{s, t} is wrong");
  }
  printf("Accepted: %d\n", num_calls);
  return 0;
}
 
*/

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:42:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |  for(i=0; i<U.size(); i++){
      |           ~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 33 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31