#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;
int a[m], b[m];
for (int i = 0; i < m; i++)
cin >> a[i] >> b[i];
for (int i = 20; i < (1 << m); i++) {
bool x[n + 1] = {}, y[n + 1] = {};
for (int j = 0; j < m; j++) {
if ((i >> j) & 1) {
if (a[j] <= b[j]) {
for (int k = a[j]; k <= b[j]; k++) {
x[k] = 1;
}
} else {
for (int k = a[j]; k <= n; k++) x[k] = 1;
for (int k = 1; k <= b[j]; k++) x[k] = 1;
}
} else {
if (a[j] <= b[j]) {
for (int k = a[j]; k <= b[j]; k++) {
y[k] = 1;
}
} else {
for (int k = a[j]; k <= n; k++) y[k] = 1;
for (int k = 1; k <= b[j]; k++) y[k] = 1;
}
}
} bool f = 1;
for (int j = 1; j <= n; j++) {
if (!x[j] || !y[j]) f = 0;
}
if (f || i == 20) {
for (int j = 0; j < m; j++) {
cout << (i >> j) % 2;
} return;
}
} cout << "impossible";
}
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);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
'impossible' claimed, but there is a solution |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
'impossible' claimed, but there is a solution |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
'impossible' claimed, but there is a solution |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
7 ms |
1884 KB |
'impossible' claimed, but there is a solution |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
'impossible' claimed, but there is a solution |
| 3 |
Halted |
0 ms |
0 KB |
- |
