Submission #799021

#	Time	Username	Problem	Language	Result	Execution time	Memory
799021		vjudge1	Port Facility (JOI17_port_facility)	C++17	10 / 100	172 ms	332 KiB

port_facility

#ifdef Home
#define _GLIBCXX_DEBUG
#endif // Home

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

main() {
#ifdef Home
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif // Home
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n;
    cin >> n;
    int tm[2 * n];
    for(int i = 1, a, b; i <= n; ++ i) {
        cin >> a >> b;
        -- a;
        -- b;
        tm[a] = i + 1;
        tm[b] = - (i + 1);
    }
    if(n < 21) {
        ll ans = 0;
        for(int msk = (1<<n); msk --> 0;) {
            stack < int > A, B;
            for(int i = 0; i < 2 * n; ++ i) {
                if(tm[i] > 0) {
                    if((1<<(tm[i] - 1))&msk) {
                        B.push(tm[i]);
                    } else {
                        A.push(tm[i]);
                    }
                } else {
                    if((1<<(-tm[i] - 1))&msk) {
                        if(B.empty() || B.top() != -tm[i]) {
                            goto BREAK;
                        } 
                        B.pop();
                    } else {
                        if(A.empty() || A.top() != -tm[i]) {
                            goto BREAK;
                        }
                        A.pop();
                    }
                }
            }
            ++ ans;
            BREAK: {
            };
        }
        cout << ans;
    }
}

Compilation message (stderr)

port_facility.cpp:12:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   12 | main() {
      | ^~~~

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