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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#211108#5487. Movie NighthagryWA 1ms6572kbC++142.0kb2023-10-12 09:52:372023-10-12 09:52:38

Judging History

你现在查看的是最新测评结果

  • [2023-10-12 09:52:38]
  • 评测
  • 测评结果:WA
  • 用时:1ms
  • 内存:6572kb
  • [2023-10-12 09:52:37]
  • 提交

answer

#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define MP make_pair
#define all(x) x.begin(),x.end()
#define Hagry ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);

using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;
using vpi = vector <pair<int, int>>;
using vvi = vector <vector<int>>;

const int OO = 1e9 + 5;
const int N = 1e5 + 5;
const int MOD = 1e9 + 7;

ll sub(ll a, ll b) {
    a -= b;
    if (a < 0) a += MOD;
    return a;
}

ll mul(ll a, ll b) { return a * b % MOD; }


vi from[N];
bool inCycle[N];
// 0 not vis, 1 vis in cur loop, 2 vis in prev loop
int vis[N], nxt[N], cycID[N], sNode, numCyc;

bool dfs(int u){
    if(vis[u] == 2)return false;
    if(vis[u] == 1){
        sNode = u;
        inCycle[u] = true;
        cycID[u] = ++numCyc;
        return true;
    }

    vis[u] = 1;
    bool inCyc = dfs(nxt[u]);
    inCycle[u] = inCyc;
    if(inCyc && sNode == u){
        inCyc = false;
        cycID[u] = numCyc;
    }
    vis[u] = 2;
    return inCyc;
}

ll dfs2(int u){
    ll ways = 1;
    for(auto e:from[u]){
        if(inCycle[e])continue;
        ways = mul(ways, dfs2(e)+1);
    }
    return ways;
}


void TC(){
    int n;
    cin >> n;

    for(int i=1; i<=n; ++i){
        cin >> nxt[i];
        from[nxt[i]].pb(i);
    }

    for(int i=1; i<=n; ++i){
        if(vis[i])continue;
        dfs(i);
    }

    vector<ll> cycWays(numCyc+1, 1);
    for(int i=1; i<=n; ++i){
        if(inCycle[i])
            cycWays[cycID[i]] = mul(cycWays[cycID[i]], dfs2(i));
    }

    ll ans = 1;
    for(int i=1; i<=numCyc; ++i)
        ans = mul(ans, cycWays[i]+1);

    ans = sub(ans, 1);
    cout << ans;
}

int32_t main() {
#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
#endif
    Hagry
    int t = 1;
//    cin >> t;
    while (t--) {
        TC();
        cout << '\n';
    }
    return 0;
}

詳細信息

Test #1:

score: 100
Accepted
time: 1ms
memory: 6040kb

input:

4
2
3
4
3

output:

3

result:

ok single line: '3'

Test #2:

score: 0
Accepted
time: 1ms
memory: 6364kb

input:

5
2
3
1
5
4

output:

3

result:

ok single line: '3'

Test #3:

score: 0
Accepted
time: 1ms
memory: 6016kb

input:

6
2
4
2
6
1
3

output:

3

result:

ok single line: '3'

Test #4:

score: -100
Wrong Answer
time: 0ms
memory: 6572kb

input:

8
2
3
4
1
3
3
1
4

output:

2

result:

wrong answer 1st lines differ - expected: '16', found: '2'