Submission #241705

#TimeUsernameProblemLanguageResultExecution timeMemory
241705atoizDuathlon (APIO18_duathlon)C++14
0 / 100
72 ms17412 KiB
/*input 4 4 1 2 2 3 3 4 4 2 4 3 1 2 3 4 4 1 5 4 1 2 2 3 3 4 4 5 4 3 1 2 2 3 3 4 */ #include <stdio.h> #define N 100007 #define M 400007 int n, m, to[M], nx[M], st[N], low[N], vis[N], ts, stk[N], instack[N], *top = &stk[0]; int bto[N * 4], bnx[N * 4], bst[N * 2], b, bm, bsz[N * 2]; long long ans = 0; inline void minimize(int &i, int j) { (i > j ? i = j : 0); } void build(int u, int p) { low[u] = vis[u] = ++ts; instack[*(++top) = u] = 1; int i, v, w, c = 0; for (i = st[u]; i; i = nx[i]) if (to[i] != p) { v = to[i]; if (!vis[v]) { ++c; build(v, u); if (low[v] >= vis[u]) { ++b; bool cont = true; while (cont) { instack[w = (*top--)] = 0; cont = (w != v); ++bm, bnx[bm] = bst[w], bto[bst[w] = bm] = b; ++bm, bnx[bm] = bst[b], bto[bst[b] = bm] = w; } ++bm, bnx[bm] = bst[b], bto[bst[b] = bm] = u; ++bm, bnx[bm] = bst[u], bto[bst[u] = bm] = b; } minimize(low[u], low[v]); } else if (instack[v]) { minimize(low[u], vis[v]); } } } void solve(int u, int p) { int i, v, d = 0; long long x = 0; bsz[u] = (u <= n); for (i = bst[u]; i; i = bnx[i]) if (bto[i] != p) { solve(v = bto[i], u), bsz[u] += bsz[v], ++d; x += (long long) bsz[v] * (bsz[v] - 1); } if (u > n) { x += (long long) (n - bsz[u]) * (n - bsz[u] - 1); ans -= x * d; } } int main() { int i, u, v; scanf("%d %d", &n, &m); for (i = 1; i <= m; ++i) { scanf("%d %d", &u, &v); nx[i * 2] = st[u], to[st[u] = i * 2] = v; nx[i * 2 - 1] = st[v], to[st[v] = i * 2 - 1] = u; } b = n, build(1, 0); ans = (long long) n * (n - 1) * (n - 2), solve(1, 0); printf("%lld", ans); }

Compilation message (stderr)

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:86:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
count_triplets.cpp:88:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
   ~~~~~^~~~~~~~~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...