Submission #877240

#	Time	Username	Problem	Language	Result	Execution time	Memory
877240		wii	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	366 ms	110520 KiB

riggedroads

#include <bits/stdc++.h>
using namespace std;

typedef double db;
typedef long long ll;
typedef long double ld;

#define int ll
typedef pair<int, int> pii;

#define lx (id << 1)
#define rx (lx | 1)
#define gcd __gcd
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define bit(i, mask) ((mask) >> (i) & 1)
#define reset(x, val) memset(x, val, sizeof(x))
#define foru(i,a,b) for(int i = (a); i <= (b); ++i)
#define ford(i,a,b) for(int i = (a); i >= (b); --i)
#define FastIO ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

template<typename T> bool maximize(T &res, const T &val) { if (res < val) { res = val; return true; } return false; }
template<typename T> bool minimize(T &res, const T &val) { if (val < res) { res = val; return true; } return false; }

const ll Linf = 0x3f3f3f3f3f3f3f3f;
const int Inf = 0x3f3f3f3f;
const ll Mod = 1e9 + 7;
const ll Mod2 = ll(1e9) + 9;
const int Lim = 1e6 + 5;
const int inv6 = 166666668;

// #define Sieve
#ifdef Sieve
    vector<int> pr;
    vector<int> lpf;
    void Linear_sieve(int n = Lim) {
        pr.assign(1, 2);
        lpf.assign(n + 1, 2);

        for (int x = 3; x <= n; x += 2) {
            if (lpf[x] == 2) pr.push_back(lpf[x] = x);
            for (int i = 1; i < pr.size() && pr[i] <= lpf[x] && pr[i] * x <= n; ++i)
                lpf[pr[i] * x] = pr[i];
        }
    }
#endif

/// ====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====

const int base = 3;
const int N = 3e5 + 5;
const int K = log2(N) + 1;
const int dx[] = {+1, -1, 0, 0};
const int dy[] = {0, 0, +1, -1};
const int block_size = sqrt(2e9) + 2;

int n, m;
int a[N];
vector<pair<int, int>> edges;

vector<pii> adj[N];
int up[N][K + 1], dep[N], par[N];
int tin[N], tout[N], timer;

struct Dsu {
	int par[N];

	Dsu() {
		memset(par, 0, sizeof par);
	}

	int root(int u) {
		return par[u] == 0 ? u : par[u] = root(par[u]);
	}

	int join(int u, int v) {
		if ((u = root(u)) == (v = root(v)))
			return false;
		
		if (dep[u] > dep[v]) swap(u, v);
		
		par[v] = u; return true;
	}

	int ok(int u, int v) {
		return root(u) != root(v);
	}
};	

void dfs(int u, int p) {
	tin[u] = ++timer;

	dep[u] = dep[p] + 1; 
	up[u][0] = p;
	foru(k, 1, K)
		up[u][k] = up[up[u][k - 1]][k - 1];

	for (auto [v, id]: adj[u]) if (v != p) {
		par[v] = id;
		dfs(v, u);
	}

	tout[u] = timer;
}

int isanc(int u, int v) {
	return tin[u] <= tin[v] && tout[v] <= tout[u];
}

int lca(int u, int v) {
	if (isanc(u, v)) return u;
	if (isanc(v, u)) return v;

	ford(k, K, 0) if (up[u][k])
		if (!isanc(up[u][k], v))
			u = up[u][k];
	return up[u][0];
}

int dist(int u, int v) {
	return dep[u] + dep[v] - 2*dep[lca(u, v)];
}

int ans[N], top;
void solve() {
    cin >> n >> m;
	foru(i, 1, m) {
		int u, v;
		cin >> u >> v;
		edges.emplace_back(u, v);
	} 

	foru(i, 1, n - 1) {
		int x; cin >> x; --x; 

		int u = edges[x].first, v = edges[x].second;
		
		adj[u].emplace_back(v, x);
		adj[v].emplace_back(u, x);

		a[x] = true;
	}

	dfs(1, 0);

	Dsu St;
	for (int i = 0; i < m; ++i) if (ans[i] == 0) {
		int u = edges[i].first;
		int v = edges[i].second;

		int w = lca(u, v);

		static vector<int> f;
		if (!f.empty()) f.clear();

		for (int x = St.root(u); dep[x] > dep[w]; x = St.root(u)) {
			int id = par[x];
			int p = up[x][0];

			f.push_back(id);

			St.join(x, p);
		}

		for (int x = St.root(v); dep[x] > dep[w]; x = St.root(v)) {
			int id = par[x];
			int p = up[x][0];

			f.push_back(id);

			St.join(x, p);
		}

		sort(all(f));
		for (int &id: f) {
			ans[id] = ++top;
		}

		if (ans[i] == 0) ans[i] = ++top;
	}

	for (int i = 0; i < m; ++i)
		cout << ans[i] << " \n"[i == m];
}

signed main() {
    FastIO;

    #define task ""
    if (fopen(task".inp", "r")) {
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}

    #define task "test"
    if (fopen(task".inp", "r")) {
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}

    #ifdef Sieve
        Linear_sieve();
    #endif

    int ntest = 1;
    // cin >> ntest;
    while (ntest--) {
        //cout << "Case " << q << ": " << "\n"; 
        solve();
        cout << "\n";
    }

    return 0;
}

/**  /\_/\
 *  (= ._.)
 *  / >TL \>AC
**/

Compilation message (stderr)

riggedroads.cpp:195: warning: "task" redefined
  195 |     #define task "test"
      | 
riggedroads.cpp:189: note: this is the location of the previous definition
  189 |     #define task ""
      | 
riggedroads.cpp: In function 'int main()':
riggedroads.cpp:191:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  191 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
riggedroads.cpp:192:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  192 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
riggedroads.cpp:197:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  197 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
riggedroads.cpp:198:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  198 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 32 / 32