Submission #31324

#	Time	Username	Problem	Language	Result	Execution time	Memory
31324		abcdef6199	Port Facility (JOI17_port_facility)	C++98	22 / 100	33 ms	2044 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
typedef pair<int, int> II;

const int MAXN = 2000 + 10;
const int MOD  = (int) 1e9 + 7;
int n, a[MAXN], b[MAXN], c[MAXN];
bool ok;

void DFS(int u) {
	for (int v = 1; v <= n; ++v) {
		bool check1 = a[u] < a[v] && a[v] < b[u] && b[u] < b[v];
		bool check2 = a[v] < a[u] && a[u] < b[v] && b[v] < b[u];
		if (check1 || check2) {
			if (c[v] == -1) {
				c[v] = c[u] ^ 1;
				DFS(v);
			}
			else {
				if (c[v] == c[u]) ok = false;
			}
		}
	}
}

int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) scanf("%d%d", &a[i], &b[i]);

	int ans = 1; ok = true;
	for (int i = 1; i <= n; ++i) c[i] = -1;
	for (int i = 1; i <= n; ++i) if (c[i] == -1) {
		c[i] = 0; DFS(i);
		ans = (ans * 2) % MOD;
	}
	
	if (ok == false) puts("0"); else printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:29:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
port_facility.cpp:30:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 1; i <= n; ++i) scanf("%d%d", &a[i], &b[i]);
                                                          ^

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22