#include <iostream>
#include <vector>
#include <cassert>
#include <set>
using ll = long long;
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) < (b)) ? (b) : (a))
int const nmax = 100000;
int const sigma = 10;
int mult[1 + nmax], acc[1 + nmax], sz[1 + nmax];
int level[1 + nmax];
int ptr = 0;
int start[1 + nmax], nxt[1 + 2 * nmax], val[1 + 2 * nmax];
void add_edge(int node, int to) {
if(start[node] == 0) {
start[node] = ++ptr;
val[ptr] = to;
} else {
nxt[++ptr] = start[node];
start[node] = ptr;
val[ptr] = to;
}
}
std::set<std::pair<int,int>> answer;
int far[1 + sigma][1 + nmax];
int jump(int gala) {
if(mult[gala] != gala)
mult[gala] = jump(mult[gala]);
return mult[gala];
}
void initialize(int n) {
for(int i = 1; i <= n; i++)
mult[i] = i;
for(int i = 1;i <= n; i++)
sz[i] = 1;
}
bool isconnected(int gala, int galb) {
return jump(gala) == jump(galb);
}
void clean(int node, int parent) {
if(0 < start[node]) {
for(int h = start[node]; 0 < h; h = nxt[h]) {
int to = val[h];
if(to != parent) {
clean(to, node);
acc[node] += acc[to];
}
}
}
if(0 < acc[node]) {
answer.erase({node, parent});
answer.erase({parent, node});
}
}
void refresh(int node, int parent) {
acc[node] = 0;
level[node] = level[parent] + 1;
far[0][node] = parent;
for(int h = 1; h <= sigma; h++)
far[h][node] = far[h - 1][far[h - 1][far[h - 1][far[h - 1][node]]]];
for(int h = start[node]; 0 < h; h = nxt[h]) {
int to = val[h];
if(to != parent)
refresh(to, node);
}
}
bool unite(int x, int y) {
int gala = jump(x);
int galb = jump(y);
if(gala == galb)
return false;
else {
if(sz[galb] < sz[gala]){
std::swap(x, y);
std::swap(gala, galb);
}
clean(gala, 0);
add_edge(x, y);
add_edge(y, x);
refresh(x, y);
mult[gala] = galb;
sz[galb] += sz[gala];
answer.insert({x, y});
return true;
}
}
int getlca(int x, int y) {
if(level[x] < level[y])
std::swap(x, y);
for(int h = sigma; 0 <= h; h--)
while(level[y] <= level[x] - (1 << (2 * h)))
x = far[h][x];
if(x == y)
return x;
for(int h = sigma; 0 <= h; h--)
while(far[h][x] != far[h][y]) {
x = far[h][x];
y = far[h][y];
}
return far[0][x];
}
void add_chain(int x, int y) {
acc[getlca(x, y)] -= 2;
acc[x]++;
acc[y]++;
}
int main() {
std::ios::sync_with_stdio(0);
std::cin.tie(0);
int n, m;
std::cin >> n >> m;
initialize(n);
for(int i = 1;i <= m; i++) {
int x, y;
std::cin >> x >> y;
if(unite(x, y) == false)
add_chain(x, y);
}
for(int i = 1;i <= n; i++)
if(mult[i] == i)
clean(i, 0);
for(std::set<std::pair<int,int>>::iterator it = answer.begin(); it != answer.end(); it++)
std::cout << it->first << " " << it->second << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
1024 KB |
Output is correct |
2 |
Correct |
8 ms |
896 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
191 ms |
896 KB |
Output is correct |
2 |
Correct |
180 ms |
888 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
374 ms |
1664 KB |
Output is correct |
2 |
Correct |
419 ms |
1664 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
668 ms |
3320 KB |
Output is correct |
2 |
Correct |
565 ms |
4344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1079 ms |
9076 KB |
Output is correct |
2 |
Correct |
1044 ms |
9336 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1840 ms |
10464 KB |
Output is correct |
2 |
Correct |
1605 ms |
10488 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2730 ms |
12664 KB |
Output is correct |
2 |
Runtime error |
2756 ms |
54280 KB |
Memory limit exceeded |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3337 ms |
12772 KB |
Output is correct |
2 |
Correct |
3317 ms |
16340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3974 ms |
12272 KB |
Output is correct |
2 |
Runtime error |
3645 ms |
31140 KB |
Memory limit exceeded |