Submission #734548

#	Time	Username	Problem	Language	Result	Execution time	Memory
734548		DAleksa	Senior Postmen (BOI14_postmen)	C++17	100 / 100	454 ms	77552 KiB

postmen

#include <bits/stdc++.h>

using namespace std;

struct edge {
    int v;
    int id;
};

const int N = 5e5 + 10;
vector<edge> g[N];
int n, m;
vector<int> eulerian_cycle;
bool mark[N];
int cnt[N];
int id = 0;
stack<int> stk;
int idx[N];

void find_eulerian_cycle(int u) {
    for(; idx[u] < (int)g[u].size(); idx[u]++) {
        edge v = g[u][idx[u]];
        if(mark[v.id]) continue;
        mark[v.id] = true;
        find_eulerian_cycle(v.v);
        eulerian_cycle.push_back(v.v);
    }
}

int main() {
    scanf("%d%d", &n, &m);
    for(int i = 0; i < m; i++) {
        int u, v;
        scanf("%d%d", &u, &v);
//        int I = i / 3;
//        if(i % 3 == 0) {
//            u = 1;
//            v = 2 * I + 2;
//        } else if(i % 3 == 1) {
//            u = 1;
//            v = 2 * I + 3;
//        } else {
//            u = 2 * I + 2;
//            v = 2 * I + 3;
//        }
        g[u].push_back({v, id});
        g[v].push_back({u, id++});
    }
    find_eulerian_cycle(1);
    eulerian_cycle.push_back(1);
    //for(int i = 0; i < eulerian_cycle.size(); i++) printf("%d ", eulerian_cycle[i]);
    //printf("\n\n");
    stk.push(eulerian_cycle[0]);
    cnt[eulerian_cycle[0]]++;
    for(int i = 1; i < eulerian_cycle.size(); i++) {
        if(cnt[eulerian_cycle[i]] > 0) {
            printf("%d ", eulerian_cycle[i]);
            while(stk.top() != eulerian_cycle[i]) {
                printf("%d ", stk.top());
                cnt[stk.top()]--;
                stk.pop();
            }
            printf("\n");
        } else {
            cnt[eulerian_cycle[i]]++;
            stk.push(eulerian_cycle[i]);
        }
    }
    return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |     for(int i = 1; i < eulerian_cycle.size(); i++) {
      |                    ~~^~~~~~~~~~~~~~~~~~~~~~~
postmen.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
postmen.cpp:34:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

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