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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#188553 | #5487. Movie Night | beshoyhany# | WA | 5ms | 18988kb | C++20 | 3.0kb | 2023-09-25 23:43:14 | 2023-09-25 23:43:15 |
Judging History
answer
#include<bits/stdc++.h>
#define ll long long
#define pp push_back
#define endl '\n'
#define all(x) x.begin(),x.end()
#define ld long double
#define PI acos(-1)
#define sin(a) sin((a)*PI/180)
#define cos(a) cos((a)*PI/180)
#define ones(x) __builtin_popcountll(x)
//#define int ll
using namespace std;
void Drakon() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
#ifdef Clion
freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}
unsigned long long inf = 1e10;
const double EPS = 1e-6;
const int MOD = 1000000007, N = 200005, LOG = 25;
ll gcd(ll x, ll y) {
return y ? gcd(y, x % y) : x;
}
ll lcm(ll a, ll b) {
return (a * b) / __gcd(a, b);
}
ll mul(const ll &a, const ll &b) {
return (a % MOD + MOD) * (b % MOD + MOD) % MOD;
}
ll add(const ll &a, const ll &b) {
return (a + b + 2 * MOD) % MOD;
}
ll pw(ll x, ll y) {
ll ret = 1;
while (y > 0) {
if (y % 2 == 0) {
x = mul(x, x);
y = y / 2;
} else {
ret = mul(ret, x);
y = y - 1;
}
}
return ret;
}
int n;
vector<int> adj[N], adj_r[N], adj_scc[N], topo;
bool vis[N];
void dfs1(int u) {
vis[u] = true;
for (auto v: adj[u]) {
if (vis[v])continue;
dfs1(v);
}
topo.pp(u);
}
int comp[N];
void dfs2(int u, int cur) {
vis[u] = true;
comp[u] = cur;
for (auto v: adj_r[u]) {
if (vis[v])continue;
dfs2(v, cur);
}
}
int c;
void scc() {
for (int i = 0; i < n; ++i) {
if (!vis[i])
dfs1(i);
}
reverse(all(topo));
memset(vis, false, sizeof vis);
for (int i = 0; i < topo.size(); ++i) {
if (!vis[topo[i]])
dfs2(topo[i], c++);
}
for (int i = 0; i < n; ++i) {
for (auto v: adj[i]) {
if (comp[i] != comp[v]) {
adj_scc[comp[i]].pp(comp[v]);
}
}
}
}
int par[N], sz[N];
void init() {
for (int i = 0; i < n; ++i) {
par[i] = i;
sz[i] = 1;
}
}
int get(int u) {
return par[u] == u ? u : par[u] = get(par[u]);
}
void join(int x, int y) {
int u = get(x), v = get(y);
if (u == v)return;
if (sz[u] > sz[v])
swap(u, v);
par[u] = v;
sz[v] += sz[u];
}
void solve() {
cin >> n;
for (int i = 0; i < n; ++i) {
int x;
cin >> x;
x--;
adj[i].pp(x);
adj_r[x].pp(i);
}
scc();
init();
for (int i = 0; i < c; ++i) {
for(auto v : adj_scc[i])join(i, v);
}
vector<int>freq(c);
for (int i = 0; i < c; ++i) {
freq[get(i)] ++;
}
int ans = 1;
for (int i = 0; i < c; ++i) {
ans = mul(ans, freq[i] + 1);
}
cout << add(ans, -1);
}
signed main() {
Drakon();
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
Details
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Test #1:
score: 100
Accepted
time: 5ms
memory: 18988kb
input:
4 2 3 4 3
output:
3
result:
ok single line: '3'
Test #2:
score: 0
Accepted
time: 0ms
memory: 18156kb
input:
5 2 3 1 5 4
output:
3
result:
ok single line: '3'
Test #3:
score: 0
Accepted
time: 5ms
memory: 17892kb
input:
6 2 4 2 6 1 3
output:
3
result:
ok single line: '3'
Test #4:
score: -100
Wrong Answer
time: 3ms
memory: 18148kb
input:
8 2 3 4 1 3 3 1 4
output:
5
result:
wrong answer 1st lines differ - expected: '16', found: '5'