#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
void print(long double t) {cerr << t;}
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T> void print(T v[],T n) {cerr << "["; for(int i = 0; i < n; i++) {cerr << v[i] << " ";} cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
fastIO();
if (str != "") {
freopen((str + ".in").c_str(), "r", stdin);
freopen((str + ".out").c_str(), "w", stdout);
}
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 3e5 + 10;
long long n, m, d;
deque<int> a[N];
deque<pair<int, int>> color[N];
void solve_() {
cin >> n >> m;
vector<int> empty, non_match;
for(int i = 0; i < m; i++) {
a[i].resize(2);
cin >> a[i][0] >> a[i][1];
if(a[i][0] && a[i][1] && a[i][0] != a[i][1]) {
color[a[i][0]].push_back({32, i});
color[a[i][1]].push_back({8, i});
} else if(a[i][0] && a[i][0] != a[i][1]) {
color[a[i][0]].push_back({1, i});
}
if(!a[i][0]) {
empty.push_back(i + 1);
a[i].pop_back();
a[i].pop_back();
}
}
set<pair<int, int>> st;
for(int i = 1; i <= n; i++) {
if(color[i].empty()) continue;
st.insert({color[i][0].first + color[i][1].first, i});
}
vector<pair<int, int>> answer;
while(!st.empty()) {
auto u = *st.begin();
st.erase(st.begin());
if(u.first == 2) {
int curr_color = u.second;
int ft = color[curr_color][0].second;
int sc = color[curr_color][1].second;
answer.push_back({ft + 1, sc + 1});
// a[ft].pop_front();
empty.push_back(ft + 1);
} else if(u.first == 9) {
int curr_color = u.second;
int ft = color[curr_color][0].second;
int sc = color[curr_color][1].second;
if(color[curr_color][0].first < color[curr_color][1].first) {
swap(ft, sc);
}
answer.push_back({ft + 1, sc + 1});
// a[ft].pop_back();
int need_to_update = a[ft][0];
int sum = color[need_to_update][0].first + color[need_to_update][1].first;
auto need_to_find = st.find({sum, need_to_update});
// assert(need_to_find != st.end());
st.erase(need_to_find);
if(color[need_to_update][0].second == ft) {
color[need_to_update][0].first = 1;
} else {
color[need_to_update][1].first = 1;
}
st.insert({color[need_to_update][0].first + color[need_to_update][1].first, need_to_update});
} else if(u.first == 16) {
if(empty.empty()) {
cout << -1 << endl;
return;
}
int curr_color = u.second;
int ft = color[curr_color][0].second;
int sc = color[curr_color][1].second;
auto empty_pos = empty.back();
empty.pop_back();
answer.push_back({ft + 1, empty_pos});
answer.push_back({sc + 1, empty_pos});
{
a[ft].pop_back();
int need_to_update = a[ft][0];
int sum = color[need_to_update][0].first + color[need_to_update][1].first;
auto need_to_find = st.find({sum, need_to_update});
if(need_to_find != st.end()) {
st.erase(need_to_find);
}
if(color[need_to_update][0].second == ft) {
color[need_to_update][0].first = 1;
} else {
color[need_to_update][1].first = 1;
}
st.insert({color[need_to_update][0].first + color[need_to_update][1].first, need_to_update});
}
{
ft = sc;
a[ft].pop_back();
int need_to_update = a[ft][0];
int sum = color[need_to_update][0].first + color[need_to_update][1].first;
auto need_to_find = st.find({sum, need_to_update});
if(need_to_find != st.end()) {
st.erase(need_to_find);
}
if(color[need_to_update][0].second == ft) {
color[need_to_update][0].first = 1;
} else {
color[need_to_update][1].first = 1;
}
st.insert({color[need_to_update][0].first + color[need_to_update][1].first, need_to_update});
}
} else if(u.first == 40 || u.first == 33) {
if(empty.empty()) {
cout << -1 << endl;
return;
}
int curr_color = u.second;
int ft = color[curr_color][0].second;
int sc = color[curr_color][1].second;
if(color[curr_color][0].first < color[curr_color][1].first) {
swap(ft, sc);
}
// dbg(ft)
// ft takna
auto empty_pos = empty.back();
empty.pop_back();
{
//taki vriny qcum enq empty_pos
answer.push_back({ft + 1, empty_pos});
{
// hanum qcum enq
a[empty_pos].push_back(a[ft].back());
// dbg(a[empty_pos])
a[ft].pop_back();
int need_to_update = a[empty_pos][0];
int sum = color[need_to_update][0].first + color[need_to_update][1].first;
auto need_to_find = st.find({sum, need_to_update});
if(need_to_find != st.end()) {
st.erase(need_to_find);
}
// dbg(color[need_to_update][0])
// dbg(color[need_to_update][1])
if(color[need_to_update][0].second == ft) {
color[need_to_update][0].first = 1;
color[need_to_update][0].second = empty_pos;
} else {
color[need_to_update][1].first = 1;
color[need_to_update][1].second = empty_pos;
}
st.insert({color[need_to_update][0].first + color[need_to_update][1].first, need_to_update});
}
int need_to_update = a[ft][0];
if(color[need_to_update][0].second == ft) {
color[need_to_update][0].first = 1;
} else {
color[need_to_update][1].first = 1;
}
st.insert({color[need_to_update][0].first + color[need_to_update][1].first, need_to_update});
}
} else {
cout << -1 << endl;
return;
}
}
cout << sz(answer) << endl;
for(auto i: answer) {
cout << i.first << " " << i.second << endl;
}
}
int main () {
setIO("");
auto solve = [&](int test_case)-> void {
while(test_case--) {
solve_();
}
};
int test_cases = 1;
// cin >> test_cases;
solve(test_cases);
return 0;
}
Compilation message
Main.cpp: In function 'void setIO(std::string)':
Main.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
65 | freopen((str + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:66:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
66 | freopen((str + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
222 ms |
404172 KB |
Output is correct |
| 2 |
Correct |
232 ms |
404192 KB |
Output is correct |
| 3 |
Correct |
239 ms |
404168 KB |
Output is correct |
| 4 |
Execution timed out |
2098 ms |
404196 KB |
Time limit exceeded |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
432 ms |
410192 KB |
Output is correct |
| 2 |
Correct |
495 ms |
411640 KB |
Output is correct |
| 3 |
Correct |
413 ms |
408728 KB |
Output is correct |
| 4 |
Correct |
375 ms |
408796 KB |
Output is correct |
| 5 |
Correct |
490 ms |
411292 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
227 ms |
404152 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
227 ms |
404152 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
236 ms |
404252 KB |
Output is correct |
| 2 |
Correct |
237 ms |
404284 KB |
Output is correct |
| 3 |
Correct |
232 ms |
404172 KB |
Output is correct |
| 4 |
Runtime error |
562 ms |
524288 KB |
Execution killed with signal 6 |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
222 ms |
404172 KB |
Output is correct |
| 2 |
Correct |
232 ms |
404192 KB |
Output is correct |
| 3 |
Correct |
239 ms |
404168 KB |
Output is correct |
| 4 |
Execution timed out |
2098 ms |
404196 KB |
Time limit exceeded |
| 5 |
Halted |
0 ms |
0 KB |
- |
