Submission #1066754

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066754		sleepntsheep	Alternating Current (BOI18_alternating)	C++17	0 / 100	25 ms	1620 KiB

alternating

#include <stdio.h>
#include <algorithm>
#include <vector>
#include <utility>

using namespace std;

using iii = pair<pair<int, int>, int>;

int n, m;
char ans[1<<18];

iii a[1<<18];

int main() {
	scanf("%d%d", &n, &m);
	for (int i = 0; i < m; ++i) scanf("%d%d", &a[i].first.first, &a[i].first.second), a[i].second = i;
	sort(a, a + m);

	int e1 = 0, e2 = 0;
	for (int j = 0, i = 1; i <= n; ++i) {
		while (j < m and a[j].first.first == i) {
			if (e1 <= e2) {
				e1 = max(e1, a[j].first.second);
				ans[a[j].second] = '1';
			} else {
				e2 = max(e2, a[j].first.second);
				ans[a[j].second] = '0';
			}
			++j;
		}
		if (e1 + 1 < i or e2 + 1 < i) {
			puts("impossible");
			return 0;
		}
	}
	
	puts(ans);
	return 0;
}

Compilation message (stderr)

alternating.cpp: In function 'int main()':
alternating.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
alternating.cpp:17:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |  for (int i = 0; i < m; ++i) scanf("%d%d", &a[i].first.first, &a[i].first.second), a[i].second = i;
      |                              ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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