제출 #650024

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
650024		alvinpiter	Tropical Garden (IOI11_garden)	C++17	49 / 100	16 ms	9860 KiB

garden

#include "garden.h"
#include "gardenlib.h"
#include<bits/stdc++.h>
using namespace std;
#define MAXN 150000
#define MAXE 300000
#define MAXLG 18

struct DirectedEdge {
  int id, from, to, beauty;
  DirectedEdge(int id_, int from_, int to_, int beauty_): id(id_), from(from_), to(to_), beauty(beauty_) {}
  bool operator<(DirectedEdge other) const {
    return beauty < other.beauty;
  }
};

vector<DirectedEdge> directedEdges, goingOutEdges[MAXN + 3];
int nxt[MAXE + 3][MAXLG + 3];

void count_routes(int n, int m, int p, int r[][2], int q, int g[]) {
  int numberOfDirectedEdges = 0;
  for (int i = 0; i < m; i++) {
    int u = r[i][0], v = r[i][1], beauty = i;

    DirectedEdge uvEdge = DirectedEdge(numberOfDirectedEdges++, u, v, beauty);
    DirectedEdge vuEdge = DirectedEdge(numberOfDirectedEdges++, v, u, beauty);

    directedEdges.push_back(uvEdge);
    goingOutEdges[u].push_back(uvEdge);

    directedEdges.push_back(vuEdge);
    goingOutEdges[v].push_back(vuEdge);
  }

  for (int i = 0; i < n; i++) {
    sort(goingOutEdges[i].begin(), goingOutEdges[i].end());
  }

  // cout << "\ngoingOutEdges\n";
  // for (int i = 0; i < n; i++) {
  //   cout << i << ":";
  //   for (auto edge: goingOutEdges[i]) {
  //     cout << " (" << edge.id << ", " << edge.from << ", " << edge.to << ", " << edge.beauty << ")";
  //   }
  //   cout << endl;
  // }

  for (auto directedEdge: directedEdges) {
    int firstEdgeId = directedEdge.id;
    int secondEdgeId;

    if (goingOutEdges[directedEdge.to].size() == 1) {
      secondEdgeId = goingOutEdges[directedEdge.to][0].id;
    } else {
      for (auto goingOutEdge: goingOutEdges[directedEdge.to]) {
        if (goingOutEdge.beauty != directedEdge.beauty) {
          secondEdgeId = goingOutEdge.id;
          break;
        }
      }
    }

    nxt[firstEdgeId][0] = secondEdgeId;
  }

  // cout << "\nnxt\n";
  // for (int i = 0; i < numberOfDirectedEdges; i++) {
  //   cout << i << ": " << nxt[i][0] << endl;
  // }

  for (int lg = 1; lg <= MAXLG; lg++) {
    for (int i = 0; i < numberOfDirectedEdges; i++) {
      nxt[i][lg] = nxt[nxt[i][lg - 1]][lg - 1];
    }
  }

  for (int i = 0; i < q; i++) {
    int ans = 0;
    for (int startingNode = 0; startingNode < n; startingNode++) {
      int currentEdgeId = goingOutEdges[startingNode][0].id;

      // Jump (g[i] - 1) times
      int numJumps = g[i] - 1;
      for (int lg = 0; lg <= MAXLG; lg++) {
        if (numJumps & (1 << lg)) {
          currentEdgeId = nxt[currentEdgeId][lg];
        }
      }

      if (directedEdges[currentEdgeId].to == p) {
        ans += 1;
      }
    }

    answer(ans);
  }
}

컴파일 시 표준 에러 (stderr) 메시지

garden.cpp: In function 'void count_routes(int, int, int, int (*)[2], int, int*)':
garden.cpp:63:25: warning: 'secondEdgeId' may be used uninitialized in this function [-Wmaybe-uninitialized]
   63 |     nxt[firstEdgeId][0] = secondEdgeId;
      |     ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

• Subtask 1: 49 / 49
• Subtask 2: 0 / 20
• Subtask 3: 0 / 31