oj.uz

Submission #1051991

# Submission time Handle Problem Language Result Execution time Memory
1051991 2024-08-10T10:57:12 Z otarius Alternating Current (BOI18_alternating) C++17
0 / 100
 10 ms 1884 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 Incorrect 0 ms 348 KB 'impossible' claimed, but there is a solution
2 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

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

Subtask #3
0 / 22.0

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

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 1884 KB 'impossible' claimed, but there is a solution
2 Halted 0 ms 0 KB -

Subtask #5
0 / 26.0

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