Submission #356248

#	Time	Username	Problem	Language	Result	Execution time	Memory
356248		parsabahrami	어르신 집배원 (BOI14_postmen)	C++17	55 / 100	821 ms	100716 KiB

postmen

// Call my Name and Save me from The Dark
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 5e5 + 10;
int M[N], ptr[N], from[N], to[N], n, m; vector<int> adj[N]; set<pii> tr;

void tour(int v) {
    while (ptr[v] < SZ(adj[v])) {
        int id = adj[v][ptr[v]++]; int u = from[id] ^ v ^ to[id];
        if (!M[id]) M[id] = 1, tour(u);
    }
    tr.insert({SZ(tr) + 1, v});
}

int main() {
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= m; i++) {
        scanf("%d%d", &from[i], &to[i]);
        adj[from[i]].push_back(i);
        adj[to[i]].push_back(i);
    }
    for (int i = 1; i <= n; i++) assert(!(SZ(adj[i]) & 1));
    tour(1);
    memset(M, 0, sizeof M);
    for (auto it = tr.begin(); it != tr.end(); it = tr.upper_bound(*it)) {
        if (M[it->S]) {
            for (auto it2 = tr.lower_bound({M[it->S], it->S}); it2 != it;) {
                M[it2->S] = 0;
                printf("%d ", it2->S);
                it2 = tr.erase(it2);
            }
            printf("\n");
            M[it->S] = it->F;
        } else M[it->S] = it->F;
    }
    return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
postmen.cpp:27:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   27 |         scanf("%d%d", &from[i], &to[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45