제출 #441914

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
441914		keta_tsimakuridze	통행료 (IOI18_highway)	C++14	51 / 100	310 ms	262148 KiB

highway

#include "highway.h"
#include<bits/stdc++.h>
#define f first
#define s second
using namespace std;
const int Q = 2e5 + 5;
/*
 
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <utility>
#include <vector>
///#include "highway.h"
 
namespace {
 
const int MAX_NUM_CALLS = 100;
const 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 ( int t = 0; t <  graph[v].size(); t++) {
    	pair<int,int> e = graph[v][t];
      int vv = e.first;
      int ei = e.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 timer,out[Q],pos[Q],up[Q],c[Q];
vector<int> x;
vector<pair<int,int> > V[Q];
void dfs(int u,int p) {
	
	for(int i=0;i<V[u].size();i++) {
		if(V[u][i].f != p)  up[V[u][i].f] = V[u][i].s,c[V[u][i].f] = u,dfs(V[u][i].f,u);
	}
	timer++;
	pos[timer] = u;
}
void find_pair(int n, std::vector<int> u, std::vector<int> v, int A, int B) {
  for(int i=0;i<u.size();i++){
  	V[u[i]].push_back({v[i],i});
  	V[v[i]].push_back({u[i],i});
  }
  dfs(0,-1);  
  x.resize(u.size());
  long long D = ask(x);
  int l = 1, r = n - 1,S = -1, T = 0;
  while(l<=r) {
  	int mid = (l+r)/2;
  	
  	for(int i=1;i<n;i++) {
  		if(i < mid) x[up[pos[i]]] = 1;
  		else x[up[pos[i]]] = 0;
	}
	long long d = ask(x); 
	if(d == D) { 
		S = pos[mid]; 
		l = mid + 1;
	}
	else r = mid - 1;
  }
  for(int i = 0; i<n;i++) reverse(V[i].begin(),V[i].end());
  timer = 0;
  dfs(0,-1);
	l = 1, r = n;
while(l<=r) {
  	int mid = (l+r)/2;
  	
  	for(int i=1;i<n;i++) {
  		if(i < mid) x[up[pos[i]]] = 1;
  		else x[up[pos[i]]] = 0;
	}
	long long d = ask(x); 
	if(d == D) { 
		T = pos[mid]; 
		l = mid + 1;
	}
	else r = mid - 1;
  }
  for(int i=0;i<u.size();i++) x[i] = 1;
  int e = S;
  while(e) { 
  	x[up[e]] = 0;
  	e = c[e];
  }
  if(ask(x) == D) {
  	D /= A;
  	T = S;
  	while(D--) {
  		T = c[T];
	  }
  }
  //cout<<S<<" "<<T<<endl;
  answer(S,T);
  
}
 
/*
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;
}*/

컴파일 시 표준 에러 (stderr) 메시지

highway.cpp: In function 'void dfs(int, int)':
highway.cpp:120:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |  for(int i=0;i<V[u].size();i++) {
      |              ~^~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:127:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  127 |   for(int i=0;i<u.size();i++){
      |               ~^~~~~~~~~
highway.cpp:167:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  167 |   for(int i=0;i<u.size();i++) x[i] = 1;
      |               ~^~~~~~~~~

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