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Submission #393336

# Submission time Handle Problem Language Result Execution time Memory
393336 2021-04-23T08:09:05 Z parsabahrami Duathlon (APIO18_duathlon) C++17
8 / 100
 99 ms 16368 KB 
/* There's someone in my head but it's not me */ 
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;

#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 2e5 + 10;
int n, m, c, B[N], sub[N], M[N], fr[N], H[N], low[N], to[N], S[N], rt[N]; 
vector<int> adj[N]; ll ret = 0; int f = 1;

ll C2(ll x) {
    x = max(0ll, x);
    return x * (x - 1) >> 1;
}

void preDFS(int v, int p = 0) {
    H[v] = H[p] + 1, low[v] = H[v];
    for (int id : adj[v]) {
        int u = fr[id] ^ to[id] ^ v;
        if (!H[u]) {
            preDFS(u, v);
            low[v] = min(low[u], low[v]);
            if (low[u] > H[v]) B[id] = 1;
        } else if (u != p) 
            low[v] = min(low[v], H[u]);
    }
}

int Find(int v) {
    return !rt[v] ? v : rt[v] = Find(rt[v]);
}

void Union(int u, int v) {
    u = Find(u), v = Find(v);
    if (u == v) return;
    S[v] += S[u];
    rt[u] = v;
}

void DFS(int v, int p = -1) {
    H[v] = 1, ret += S[v] * (S[v] - 1) * (S[v] - 2);
    c += S[v]; sub[v] = S[v];
    for (int id : adj[v]) {
        int u = fr[id] ^ to[id] ^ v;
        if (u != p) 
            DFS(u, v), sub[v] += sub[u];
    }
}

void SFD(int v, int p = -1) {
    ll tot = 0;
    tot += C2(c - S[v]);
    for (int id : adj[v]) {
        int u = fr[id] ^ to[id] ^ v;
        if (u != p) 
           tot -= C2(sub[u]);
    }
    tot -= C2(c - sub[v]);
    ret += tot * 2;
    for (int id : adj[v]) {
        int u = fr[id] ^ to[id] ^ v; 
        if (u != p) SFD(u, v);
    }
    ret += 2ll * (c - S[v]) * 1ll * ((S[v] - 1) * 1ll * (S[v] - 2) + (S[v] - 1));
}

void shitDFS(int v) {
    M[v] = 1, c++; f &= bool(SZ(adj[v]) > 1);
    for (int id : adj[v]) {
        int u = fr[id] ^ to[id] ^ v;
        if (!M[u]) shitDFS(u);
    }
}

void sub3() {
    for (int i = 1; i <= n; i++) 
        if (!M[i]) {
            c = 0, f = 1;
            shitDFS(i);
            if (!f) ret += 1ll * c * (c - 1) * (c - 2) / 3;
            else ret += 1ll * c * (c - 1) * (c - 2);
        }
    printf("%lld\n", ret);
    exit(0);
}

int main() {
    fill(S, S + N, 1);
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= m; i++) {
        scanf("%d%d", &fr[i], &to[i]);
        adj[fr[i]].push_back(i);
        adj[to[i]].push_back(i);
    }
    sub3();
    for (int i = 1; i <= n; i++) 
        if (!H[i]) preDFS(i);
    for (int i = 1; i <= m; i++) {
        if (!B[i]) 
            sub3(), Union(fr[i], to[i]);
    }
    for (int i = 1; i <= n; i++) 
        adj[i] = {};
    for (int i = 1; i <= m; i++) 
        if (B[i]) {
            adj[fr[i] = Find(fr[i])].push_back(i);
            adj[to[i] = Find(to[i])].push_back(i);
        }
    memset(H, 0, sizeof H);
    for (int i = 1; i <= n; i++) 
        if (!rt[i] && !H[i]) {
            c = 0;
            DFS(i);
            SFD(i);
        }
    printf("%lld\n", ret);
    return 0;
}

Compilation message

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:95:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   95 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
count_triplets.cpp:97:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   97 |         scanf("%d%d", &fr[i], &to[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5708 KB Output is correct
2 Correct 4 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 4 ms 5708 KB Output is correct
5 Correct 4 ms 5708 KB Output is correct
6 Correct 8 ms 5708 KB Output is correct
7 Incorrect 5 ms 5780 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5708 KB Output is correct
2 Correct 4 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 4 ms 5708 KB Output is correct
5 Correct 4 ms 5708 KB Output is correct
6 Correct 8 ms 5708 KB Output is correct
7 Incorrect 5 ms 5780 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 16368 KB Output is correct
2 Correct 78 ms 16256 KB Output is correct
3 Correct 75 ms 13176 KB Output is correct
4 Correct 78 ms 14704 KB Output is correct
5 Correct 67 ms 12180 KB Output is correct
6 Correct 72 ms 12140 KB Output is correct
7 Correct 61 ms 11256 KB Output is correct
8 Correct 63 ms 11716 KB Output is correct
9 Correct 66 ms 10696 KB Output is correct
10 Correct 71 ms 11204 KB Output is correct
11 Correct 99 ms 9924 KB Output is correct
12 Correct 62 ms 9804 KB Output is correct
13 Correct 51 ms 9796 KB Output is correct
14 Correct 51 ms 9620 KB Output is correct
15 Correct 74 ms 9080 KB Output is correct
16 Correct 75 ms 9040 KB Output is correct
17 Correct 5 ms 6092 KB Output is correct
18 Correct 13 ms 6092 KB Output is correct
19 Correct 5 ms 6092 KB Output is correct
20 Correct 5 ms 6092 KB Output is correct
21 Correct 6 ms 6092 KB Output is correct
22 Correct 5 ms 6092 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 5836 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 76 ms 10136 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 5836 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 62 ms 10152 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #8
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5708 KB Output is correct
2 Correct 4 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 4 ms 5708 KB Output is correct
5 Correct 4 ms 5708 KB Output is correct
6 Correct 8 ms 5708 KB Output is correct
7 Incorrect 5 ms 5780 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5708 KB Output is correct
2 Correct 4 ms 5708 KB Output is correct
3 Correct 4 ms 5708 KB Output is correct
4 Correct 4 ms 5708 KB Output is correct
5 Correct 4 ms 5708 KB Output is correct
6 Correct 8 ms 5708 KB Output is correct
7 Incorrect 5 ms 5780 KB Output isn't correct
8 Halted 0 ms 0 KB -