oj.uz

Submission #1052002

# Submission time Handle Problem Language Result Execution time Memory
1052002 2024-08-10T11:00:21 Z otarius Alternating Current (BOI18_alternating) C++17
19 / 100
 26 ms 3272 KB 
#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define ull unsigned long long
#define all(x) (x).begin(),(x).end()
 
// #define int long long
// #define int unsigned long long
 
// #define ordered_set(T) tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>
// #define ordered_multiset(T) tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>
 
void open_file(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}
 
// const ll mod = 1e9 + 7;
// const ll mod = 998244353;
 
const ll inf = 1e9;
const ll biginf = 1e18;
const int maxN = 1e5 + 25;
 
void solve() {
    int n, m;
    cin >> n >> m;
    pair<pii, int> v[m];
    for (int i = 0; i < m; i++) {
        cin >> v[i].ff.ff >> v[i].ff.sc; v[i].sc = i;
    } int ans[m];
    sort(v, v + m);
    int a = 0, b = 0;
    for (int i = 0; i < m; i++) {
        if (a < b) {
            if (a + 1 < v[i].ff.ff) {
                cout << "impossible"; return;
            } a = max(a, v[i].ff.sc); ans[v[i].sc] = 0;
        } else {
            if (b + 1 < v[i].ff.ff) {
                cout << "impossible"; return;
            } b = max(b, v[i].ff.sc); ans[v[i].sc] = 1;
        }
    } if (a != n || b != n) {
        cout << "impossible"; return;
    } for (int i = 0; i < m; i++)
        cout << ans[i];
}
int32_t main() { 
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        cout << '\n';
    }
    return 0;
}

Compilation message

alternating.cpp: In function 'void open_file(std::string)':
alternating.cpp:26:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
alternating.cpp:27:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 1880 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 5 ms 1116 KB Output is correct
4 Correct 8 ms 1116 KB Output is correct
5 Correct 16 ms 2908 KB Output is correct
6 Correct 15 ms 3164 KB Output is correct
7 Correct 15 ms 2908 KB Output is correct
8 Correct 1 ms 344 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 17 ms 3272 KB Output is correct
11 Correct 12 ms 2396 KB Output is correct
12 Correct 15 ms 2928 KB Output is correct
13 Correct 1 ms 344 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 26 ms 3168 KB Output is correct
16 Correct 6 ms 1628 KB Output is correct
17 Correct 17 ms 3016 KB Output is correct
18 Correct 17 ms 2908 KB Output is correct
19 Correct 2 ms 604 KB Output is correct
20 Correct 22 ms 3228 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -