#include <iostream>
#include <set>
#include <vector>
std::set<int> current[30010];
std::set<int> goal[30010];
bool visited[30010];
std::vector<std::pair<int, std::pair<int, int>>> res;
int n, m, a, b;
void dfs_pre(int x) {
    if (x != 1 && current[x].find(1) == current[x].end()) {
        current[x].insert(1);
        current[1].insert(x);
        res.emplace_back(1, std::pair(1, x));
    }
    visited[x] = true;
    for (int it : current[x]) if (!visited[it]) dfs_pre(it);
}
void dfs_post(int x) {
    visited[x] = true;
    for (int it : goal[x]) if (!visited[it]) dfs_post(it);
    if (x != 1 && goal[x].find(1) == goal[x].end()) {
        current[x].erase(1);
        current[1].erase(x);
        res.emplace_back(-1, std::pair(1, x));
    }
}
int main() {
    std::cin >> n;
    std::cin >> m;
    for (int i = 0; i < m; i++) {
        std::cin >> a >> b;
        current[a].insert(b);
        current[b].insert(a);
    }
    std::cin >> m;
    for (int i = 0; i < m; i++) {
        std::cin >> a >> b;
        goal[a].insert(b);
        goal[b].insert(a);
    }
    dfs_pre(1);
    for (int i = 0; i <= n; i++) {
        visited[i] = 0;
    }
    for (int i = 2; i <= n; i++) {
        for (auto it = goal[i].begin(); it != goal[i].end(); ++it) {
            if (current[i].find(*it) == current[i].end()) {
                current[i].insert(*it);
                current[*it].insert(i);
                res.emplace_back(1, std::pair(i, *it));
            }
        }
        for (auto it = current[i].begin(); it != current[i].end(); ) {
            if (goal[i].find(*it) == goal[i].end() && *it != 1) {
                res.emplace_back(-1, std::pair(i, *it));
                current[*it].erase(i);
                it = current[i].erase(it);
            }
            else {
                ++it;
            }
        }
    }
    dfs_post(1);
    std::cout << res.size() << "\n";
    for (auto & re : res) {
        if (re.first == -1) {
            std::cout << "- ";
        } else {
            std::cout << "+ ";
        }
        std::cout << re.second.first << " " << re.second.second << "\n";
    }
    return 0;
}
        1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94  | #include <iostream> #include <set> #include <vector> std::set<int> current[30010]; std::set<int> goal[30010]; bool visited[30010]; std::vector<std::pair<int, std::pair<int, int>>> res; int n, m, a, b; void dfs_pre(int x) { if (x != 1 && current[x].find(1) == current[x].end()) { current[x].insert(1); current[1].insert(x); res.emplace_back(1, std::pair(1, x)); } visited[x] = true; for (int it : current[x]) if (!visited[it]) dfs_pre(it); } void dfs_post(int x) { visited[x] = true; for (int it : goal[x]) if (!visited[it]) dfs_post(it); if (x != 1 && goal[x].find(1) == goal[x].end()) { current[x].erase(1); current[1].erase(x); res.emplace_back(-1, std::pair(1, x)); } } int main() { std::cin >> n; std::cin >> m; for (int i = 0; i < m; i++) { std::cin >> a >> b; current[a].insert(b); current[b].insert(a); } std::cin >> m; for (int i = 0; i < m; i++) { std::cin >> a >> b; goal[a].insert(b); goal[b].insert(a); } dfs_pre(1); for (int i = 0; i <= n; i++) { visited[i] = 0; } for (int i = 2; i <= n; i++) { for (auto it = goal[i].begin(); it != goal[i].end(); ++it) { if (current[i].find(*it) == current[i].end()) { current[i].insert(*it); current[*it].insert(i); res.emplace_back(1, std::pair(i, *it)); } } for (auto it = current[i].begin(); it != current[i].end(); ) { if (goal[i].find(*it) == goal[i].end() && *it != 1) { res.emplace_back(-1, std::pair(i, *it)); current[*it].erase(i); it = current[i].erase(it); } else { ++it; } } } dfs_post(1); std::cout << res.size() << "\n"; for (auto & re : res) { if (re.first == -1) { std::cout << "- "; } else { std::cout << "+ "; } std::cout << re.second.first << " " << re.second.second << "\n"; } return 0; }  | 
            
        
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