#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<vector>
#include<queue>
#include<bitset>
#include<string>
#include<stack>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<complex>
#include<cmath>
#include<iomanip>
#include<numeric>
#include<algorithm>
#include<list>
#include<functional>
#include<cassert>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 987654321987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a));
#define MEM_1(a) memset((a),-1,sizeof(a));
#define ALL(a) a.begin(),a.end()
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<ld, ld> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<double> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int,int,int,int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const ll MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) {ll ret=1; for(;b;b>>=1,a=(a*a)%MMM)if(b&1)ret=(ret*a)% MMM; return ret; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { if (a == 0 || b == 0)return a + b; return a*(b / gcd(a, b)); }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };
int parent[100001];
int find(int a)
{
if (parent[a] < 0)return a;
return parent[a] = find(parent[a]);
}
void merge(int a, int b)
{
a = find(a), b = find(b);
if (a != b)
{
parent[a] += parent[b];
parent[b] = a;
}
}
int n,m;
Vi v[100001];
bool chk[100001];
void dfs(int N)
{
while(!v[N].empty())
{
int next=v[N].back();
merge(N,next);
v[N].pop_back();
dfs(next);
}
}
int main() {
MEM_1(parent);
scanf("%d%d",&n,&m);
fup(i,1,m,1)
{
int x,y;
scanf("%d%d",&x,&y);
v[x].pb(y);
}
fup(i,1,n,1)
{
if(v[i].size()>=2)
{
for(int next:v[i])dfs(next);
}
fup(j,0,(int)v[i].size()-2,1)merge(v[i][j],v[i][j+1]);
}
ll ans=0;
fup(i,1,n,1)
{
int t=find(i);
if(chk[t])continue;
int sz=-parent[t];
if(sz>=2)ans+=1LL*sz*(sz-1);
else ans+=v[t].size();
chk[t]=1;
}
printf("%lld",ans);
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:93:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d",&n,&m);
~~~~~^~~~~~~~~~~~~~
friends.cpp:97:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d",&x,&y);
~~~~~^~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
3192 KB |
Output is correct |
2 |
Correct |
4 ms |
3064 KB |
Output is correct |
3 |
Correct |
5 ms |
3064 KB |
Output is correct |
4 |
Correct |
4 ms |
3064 KB |
Output is correct |
5 |
Correct |
4 ms |
3104 KB |
Output is correct |
6 |
Correct |
4 ms |
3064 KB |
Output is correct |
7 |
Correct |
5 ms |
3064 KB |
Output is correct |
8 |
Correct |
5 ms |
3192 KB |
Output is correct |
9 |
Correct |
5 ms |
3064 KB |
Output is correct |
10 |
Correct |
5 ms |
3064 KB |
Output is correct |
11 |
Correct |
4 ms |
3064 KB |
Output is correct |
12 |
Correct |
4 ms |
3064 KB |
Output is correct |
13 |
Correct |
4 ms |
3064 KB |
Output is correct |
14 |
Correct |
4 ms |
3068 KB |
Output is correct |
15 |
Correct |
4 ms |
3064 KB |
Output is correct |
16 |
Correct |
4 ms |
3064 KB |
Output is correct |
17 |
Correct |
5 ms |
3192 KB |
Output is correct |
18 |
Correct |
4 ms |
3064 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
3320 KB |
Output is correct |
2 |
Correct |
6 ms |
3192 KB |
Output is correct |
3 |
Correct |
13 ms |
3704 KB |
Output is correct |
4 |
Correct |
57 ms |
9212 KB |
Output is correct |
5 |
Correct |
43 ms |
7760 KB |
Output is correct |
6 |
Correct |
73 ms |
11712 KB |
Output is correct |
7 |
Correct |
5 ms |
3192 KB |
Output is correct |
8 |
Correct |
8 ms |
3436 KB |
Output is correct |
9 |
Correct |
14 ms |
4088 KB |
Output is correct |
10 |
Correct |
22 ms |
4984 KB |
Output is correct |
11 |
Correct |
72 ms |
11900 KB |
Output is correct |
12 |
Correct |
10 ms |
3496 KB |
Output is correct |
13 |
Correct |
7 ms |
3192 KB |
Output is correct |
14 |
Correct |
6 ms |
3192 KB |
Output is correct |
15 |
Correct |
8 ms |
3448 KB |
Output is correct |
16 |
Correct |
15 ms |
3960 KB |
Output is correct |
17 |
Correct |
66 ms |
9208 KB |
Output is correct |
18 |
Correct |
6 ms |
3192 KB |
Output is correct |
19 |
Correct |
6 ms |
3448 KB |
Output is correct |
20 |
Correct |
78 ms |
11768 KB |
Output is correct |
21 |
Correct |
6 ms |
3320 KB |
Output is correct |
22 |
Correct |
8 ms |
3192 KB |
Output is correct |
23 |
Correct |
8 ms |
3324 KB |
Output is correct |
24 |
Correct |
6 ms |
3192 KB |
Output is correct |
25 |
Correct |
6 ms |
3320 KB |
Output is correct |
26 |
Correct |
6 ms |
3196 KB |
Output is correct |
27 |
Correct |
6 ms |
3320 KB |
Output is correct |
28 |
Correct |
6 ms |
3320 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
68 ms |
11720 KB |
Output is correct |
2 |
Correct |
108 ms |
9592 KB |
Output is correct |
3 |
Correct |
103 ms |
9592 KB |
Output is correct |
4 |
Correct |
57 ms |
6264 KB |
Output is correct |
5 |
Correct |
28 ms |
4984 KB |
Output is correct |
6 |
Correct |
93 ms |
10616 KB |
Output is correct |
7 |
Correct |
83 ms |
8440 KB |
Output is correct |
8 |
Correct |
79 ms |
8312 KB |
Output is correct |
9 |
Correct |
50 ms |
6520 KB |
Output is correct |
10 |
Correct |
69 ms |
7416 KB |
Output is correct |
11 |
Correct |
116 ms |
9724 KB |
Output is correct |
12 |
Correct |
110 ms |
10796 KB |
Output is correct |
13 |
Correct |
47 ms |
7544 KB |
Output is correct |
14 |
Correct |
79 ms |
11640 KB |
Output is correct |
15 |
Correct |
29 ms |
4984 KB |
Output is correct |
16 |
Correct |
6 ms |
3324 KB |
Output is correct |
17 |
Correct |
5 ms |
3192 KB |
Output is correct |
18 |
Correct |
99 ms |
8568 KB |
Output is correct |
19 |
Correct |
102 ms |
8560 KB |
Output is correct |
20 |
Correct |
54 ms |
6008 KB |
Output is correct |
21 |
Correct |
28 ms |
4856 KB |
Output is correct |
22 |
Correct |
5 ms |
3192 KB |
Output is correct |
23 |
Correct |
36 ms |
6136 KB |
Output is correct |
24 |
Correct |
60 ms |
6236 KB |
Output is correct |
25 |
Correct |
44 ms |
7416 KB |
Output is correct |
26 |
Correct |
56 ms |
10488 KB |
Output is correct |
27 |
Correct |
100 ms |
11128 KB |
Output is correct |
28 |
Correct |
53 ms |
7032 KB |
Output is correct |
29 |
Correct |
51 ms |
7032 KB |
Output is correct |
30 |
Correct |
106 ms |
9536 KB |
Output is correct |
31 |
Correct |
55 ms |
5852 KB |
Output is correct |
32 |
Correct |
47 ms |
7388 KB |
Output is correct |
33 |
Correct |
45 ms |
7416 KB |
Output is correct |
34 |
Correct |
54 ms |
6392 KB |
Output is correct |
35 |
Correct |
48 ms |
7416 KB |
Output is correct |
36 |
Correct |
51 ms |
8572 KB |
Output is correct |
37 |
Correct |
55 ms |
7032 KB |
Output is correct |