#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 1e5;
int N, M;
ll ans;
vector<int> adj[MAXN+10], adj2[MAXN+10];
int par[MAXN+10], sz[MAXN+10];
int Find(int x) { return x==par[x] ? x : par[x]=Find(par[x]); }
void Union(int x, int y) { x=Find(x); y=Find(y); sz[y]+=sz[x]; par[x]=y; }
bool vis[MAXN+10];
int main()
{
int i, j;
scanf("%d%d", &N, &M);
for(i=1; i<=N; i++) par[i]=i, sz[i]=1;
for(i=1; i<=M; i++)
{
int u, v;
scanf("%d%d", &u, &v);
adj[u].push_back(v);
}
for(i=1; i<=N; i++)
{
for(j=1; j<adj[i].size(); j++)
{
if(Find(adj[i][0])==Find(adj[i][j])) continue;
Union(adj[i][0], adj[i][j]);
}
}
for(i=1; i<=N; i++)
{
for(auto it : adj[i])
{
int u=i, v=it;
u=Find(u), v=Find(v);
if(u!=v) adj2[u].push_back(v);//, printf("ADJ2 %d %d\n", u, v);
}
}
set<pii, greater<pii>> S;
vector<pii> V;
for(i=1; i<=N; i++) if(i==Find(i)) S.insert({sz[i], i});
while(!S.empty())
{
pii t=*S.begin(); S.erase(S.begin());
if(t.first<=1) continue;
//for(i=1; i<=N; i++) printf("%d ", Find(i)); printf("\n");
//printf("NOW %d\n", t.second);
//for(auto it : S) printf("S %d %d\n", it.first, it.second);
for(auto nxt : adj2[t.second])
{
//printf("NXT / %d %d\n", sz[Find(nxt)], nxt);
if(Find(t.second)!=Find(nxt)) V.push_back({t.second, nxt});
if(S.find({sz[Find(nxt)], nxt})==S.end()) continue;
S.erase({sz[Find(nxt)], nxt});
S.insert({sz[Find(nxt)]+sz[Find(t.second)], nxt});
}
}
for(auto it : V) if(Find(it.first)!=Find(it.second)) Union(it.first, it.second);
for(i=1; i<=N; i++)
{
for(auto it : adj[i])
{
int u=i, v=it;
if(Find(u)!=Find(v)) ans++;
}
}
for(i=1; i<=N; i++) if(i==Find(i)) ans+=(ll)sz[i]*(sz[i]-1);
//for(i=1; i<=N; i++) printf("%d ", Find(i));
printf("%lld", ans);
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:34:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=1; j<adj[i].size(); j++)
~^~~~~~~~~~~~~~
friends.cpp:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &N, &M);
~~~~~^~~~~~~~~~~~~~~~
friends.cpp:29:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &u, &v);
~~~~~^~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
8 ms |
4984 KB |
Output is correct |
2 |
Correct |
8 ms |
4984 KB |
Output is correct |
3 |
Correct |
8 ms |
4984 KB |
Output is correct |
4 |
Correct |
8 ms |
4984 KB |
Output is correct |
5 |
Correct |
8 ms |
4984 KB |
Output is correct |
6 |
Correct |
8 ms |
4984 KB |
Output is correct |
7 |
Correct |
8 ms |
4984 KB |
Output is correct |
8 |
Correct |
9 ms |
4984 KB |
Output is correct |
9 |
Correct |
9 ms |
4984 KB |
Output is correct |
10 |
Correct |
8 ms |
4984 KB |
Output is correct |
11 |
Correct |
8 ms |
4984 KB |
Output is correct |
12 |
Correct |
8 ms |
4984 KB |
Output is correct |
13 |
Correct |
8 ms |
4984 KB |
Output is correct |
14 |
Correct |
8 ms |
5112 KB |
Output is correct |
15 |
Correct |
8 ms |
5112 KB |
Output is correct |
16 |
Correct |
8 ms |
4984 KB |
Output is correct |
17 |
Correct |
8 ms |
4984 KB |
Output is correct |
18 |
Correct |
8 ms |
4984 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
5368 KB |
Output is correct |
2 |
Correct |
10 ms |
5404 KB |
Output is correct |
3 |
Correct |
17 ms |
5368 KB |
Output is correct |
4 |
Correct |
58 ms |
6008 KB |
Output is correct |
5 |
Correct |
51 ms |
6904 KB |
Output is correct |
6 |
Correct |
75 ms |
8440 KB |
Output is correct |
7 |
Correct |
9 ms |
5112 KB |
Output is correct |
8 |
Correct |
13 ms |
5240 KB |
Output is correct |
9 |
Correct |
18 ms |
5496 KB |
Output is correct |
10 |
Correct |
28 ms |
6012 KB |
Output is correct |
11 |
Correct |
73 ms |
8440 KB |
Output is correct |
12 |
Correct |
15 ms |
5368 KB |
Output is correct |
13 |
Correct |
13 ms |
5496 KB |
Output is correct |
14 |
Correct |
12 ms |
5496 KB |
Output is correct |
15 |
Correct |
13 ms |
5368 KB |
Output is correct |
16 |
Correct |
20 ms |
5624 KB |
Output is correct |
17 |
Correct |
77 ms |
8312 KB |
Output is correct |
18 |
Correct |
11 ms |
5624 KB |
Output is correct |
19 |
Correct |
12 ms |
5624 KB |
Output is correct |
20 |
Correct |
76 ms |
8312 KB |
Output is correct |
21 |
Correct |
12 ms |
5496 KB |
Output is correct |
22 |
Correct |
12 ms |
5496 KB |
Output is correct |
23 |
Correct |
13 ms |
5368 KB |
Output is correct |
24 |
Correct |
13 ms |
5496 KB |
Output is correct |
25 |
Correct |
12 ms |
5624 KB |
Output is correct |
26 |
Correct |
13 ms |
5500 KB |
Output is correct |
27 |
Correct |
11 ms |
5624 KB |
Output is correct |
28 |
Correct |
12 ms |
5752 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
68 ms |
6136 KB |
Output is correct |
2 |
Correct |
156 ms |
10488 KB |
Output is correct |
3 |
Correct |
164 ms |
12792 KB |
Output is correct |
4 |
Correct |
130 ms |
13688 KB |
Output is correct |
5 |
Correct |
83 ms |
13304 KB |
Output is correct |
6 |
Correct |
118 ms |
9720 KB |
Output is correct |
7 |
Correct |
117 ms |
12920 KB |
Output is correct |
8 |
Correct |
117 ms |
12920 KB |
Output is correct |
9 |
Correct |
105 ms |
13684 KB |
Output is correct |
10 |
Correct |
113 ms |
12920 KB |
Output is correct |
11 |
Correct |
158 ms |
12980 KB |
Output is correct |
12 |
Correct |
149 ms |
13048 KB |
Output is correct |
13 |
Correct |
101 ms |
17912 KB |
Output is correct |
14 |
Correct |
78 ms |
8592 KB |
Output is correct |
15 |
Correct |
77 ms |
13304 KB |
Output is correct |
16 |
Correct |
37 ms |
10744 KB |
Output is correct |
17 |
Correct |
35 ms |
10488 KB |
Output is correct |
18 |
Correct |
151 ms |
12024 KB |
Output is correct |
19 |
Correct |
144 ms |
12024 KB |
Output is correct |
20 |
Correct |
106 ms |
12660 KB |
Output is correct |
21 |
Correct |
87 ms |
12664 KB |
Output is correct |
22 |
Correct |
36 ms |
10488 KB |
Output is correct |
23 |
Correct |
40 ms |
6520 KB |
Output is correct |
24 |
Correct |
102 ms |
11384 KB |
Output is correct |
25 |
Correct |
99 ms |
17916 KB |
Output is correct |
26 |
Correct |
129 ms |
17912 KB |
Output is correct |
27 |
Correct |
169 ms |
13304 KB |
Output is correct |
28 |
Correct |
117 ms |
15604 KB |
Output is correct |
29 |
Correct |
126 ms |
15604 KB |
Output is correct |
30 |
Correct |
160 ms |
12700 KB |
Output is correct |
31 |
Correct |
149 ms |
13300 KB |
Output is correct |
32 |
Correct |
98 ms |
17912 KB |
Output is correct |
33 |
Correct |
95 ms |
17912 KB |
Output is correct |
34 |
Correct |
129 ms |
14836 KB |
Output is correct |
35 |
Correct |
103 ms |
17912 KB |
Output is correct |
36 |
Correct |
121 ms |
18064 KB |
Output is correct |
37 |
Correct |
114 ms |
15604 KB |
Output is correct |