#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N = 1e5 + 7;
int n, m;
ll res;
int p[N], sz[N];
set<int> out[N], in[N];
set<int> st[N];
int Find(int node) {
if(p[node] == node) return node;
p[node] = Find(p[node]);
return p[node];
}
void AddEdge(int a, int b) {
if(Find(a) == Find(b) || out[a].find(Find(b)) != out[a].end()) return;
//printf("Edge added: %d %d\n", a, Find(b));
out[a].insert(Find(b));
in[Find(b)].insert(a);
res += sz[b];
}
void RemoveEdge(int a, int b) {
//if(Find(a) == Find(b) || out[a].find(Find(b)) == out[a].end()) return;
//printf("Edge removed: %d %d\n", a, Find(b));
out[a].erase(Find(b));
in[Find(b)].erase(a);
res -= sz[Find(b)];
}
bool Union(int a, int b) {
a = Find(a);
b = Find(b);
if(a == b) return false;
if(sz[a] > sz[b]) swap(a, b);
bool ab = false, ba = false;
for(int v: st[a]) ab |= in[b].find(v) != in[b].end();
for(int v: in[a]) ba |= st[b].find(v) != st[b].end();
if(!ab || !ba) return false;
//printf("Union: %d %d\n", a, b);
vector<pair<int, int> > rem;
//printf("Removed edges\n");
for(int v: st[a]) {
if(out[v].find(b) != out[v].end()) rem.push_back({v, b});
}
for(int v: in[a]) {
if(st[b].find(v) != st[b].end()) rem.push_back({v, a});
}
//for(auto& e: rem) printf("%d %d\n", e.first, e.second);
for(auto& e: rem) RemoveEdge(e.first, e.second);
res += 2ll * sz[a] * sz[b];
//if (a == 4 && b == 2) printf("Union 4 2, res = %lld\n", res);
res += 1ll * in[b].size() * sz[a];
vector<int> vnext;
for(int v: in[a]) {
out[v].erase(a);
out[v].insert(b);
vnext.push_back(v);
if(in[b].find(v) == in[b].end()){
//printf("Redirect %d -> %d to %d\n", v, a, b);
in[b].insert(v);
res += sz[b];
} else res -= sz[a];
}
in[a] = {};
for(int v: st[a]){
for(int to: out[v]) vnext.push_back(to);
st[b].insert(v);
}
st[a] = {};
sz[b] += sz[a];
p[a] = b;
for(int v: vnext) Union(v, b);
return true;
}
void Init() {
res = 0;
for(int i = 1; i <= n; i++) {
p[i] = i;
sz[i] = 1;
out[i] = in[i] = {};
st[i] = {i};
}
}
int main() {
scanf("%d%d", &n, &m);
Init();
for(int day = 1; day <= m; day++) {
int a, b;
scanf("%d%d", &a, &b);
//printf("%d -> %d, add = %d\n", a, b, sz[b]);
AddEdge(a, b);
Union(a, b);
printf("%lld\n", res);
//printf("After day %d\n", day);
//for(int i = 1; i <= n; i++) printf("p[%d] = %d, sz[%d] = %d\n", i, p[i], i, sz[i]);
}
return 0;
}
Compilation message
joitter2.cpp: In function 'int main()':
joitter2.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
91 | scanf("%d%d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~
joitter2.cpp:95:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
95 | scanf("%d%d", &a, &b);
| ~~~~~^~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
14444 KB |
Output is correct |
| 2 |
Incorrect |
11 ms |
14444 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
14444 KB |
Output is correct |
| 2 |
Incorrect |
11 ms |
14444 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
14444 KB |
Output is correct |
| 2 |
Incorrect |
11 ms |
14444 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
