Submission #863400

#	Time	Username	Problem	Language	Result	Execution time	Memory
863400		Trisanu_Das	Alternating Current (BOI18_alternating)	C++17	55 / 100	3047 ms	4772 KiB

alternating

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
const int N = 100020;
 
int n, m;
 
int dis(int x, int y){
  if(y < x) return n + y - x + 1;
  return y - x + 1;
}
 
vector<pair<int, int> > A[100020];
int answer[100020], S[100020][2];
 
int main() {
  cin >> n >> m;
  int ci, cm; ci = cm = 0;
  for(int i = 1; i <= m; i++){
    int x, y; cin >> x >> y;
    A[x - 1].push_back(make_pair(dis(x, y), i));
    if(dis(x, y) > cm) ci = x - 1, cm = dis(x, y);
  }
  for(ci = 0; ci < n; ++ci){
    for(int p = 0; p < n; ++p) {
      int i = (p + ci) % n;
      for(int j = 0; j < A[i].size(); ++j){
        int x = A[i][j].first;
        int c = 0;
        for(int k = 0; k < n; ++k){
          int now = (i + k) % n;
          if(S[now][0] == 0){
            c = 0;
            break;
          }
          if(S[now][1] == 0) {
            c = 1;
            break;
          }
        }
        answer[A[i][j].second] = c;
        for(int k = 0; k < x; ++k) S[(i + k) % n][c] = 1;
      }
    }
    bool B = true;
    for(int i = 0; i < n; ++ i)
      if(S[i][0] == 0 || S[i][1] == 0){
        B = false; break;
      }
    if(B) break;
    for(int i = 0; i < n; ++i) S[i][0] = S[i][1] = 0;
  }
  for(int i = 0; i < n; ++ i) if(S[i][0] == 0 || S[i][1] == 0) return printf("impossible"), 0;
  for(int i = 1; i <= m; ++ i)  printf("%d", answer[i]);
}

Compilation message (stderr)

alternating.cpp: In function 'int main()':
alternating.cpp:28:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |       for(int j = 0; j < A[i].size(); ++j){
      |                      ~~^~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 22 / 22
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26