oj.uz

Submission #634602

# Submission time Handle Problem Language Result Execution time Memory
634602 2022-08-24T15:34:29 Z MohammadAghil Subtree (INOI20_subtree) C++17
12 / 100
 134 ms 36324 KB 
#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target ("avx2")
using namespace std;

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

#define rep(i,l,r) for(int i = (l); i < (r); i++)
#define per(i,r,l) for(int i = (r); i >= (l); i--)
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define pb push_back
#define ff first
#define ss second

void dbg(){
    cerr << endl;
}
template<typename Head, typename... Tail> void dbg(Head h, Tail... t){
    cerr << " " << h << ",";
    dbg(t...);
}
#define er(...) cerr << __LINE__ << " <" << #__VA_ARGS__ << ">:", dbg(__VA_ARGS__)

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void IOS(){
    cin.tie(0) -> sync_with_stdio(0);
//    #ifndef ONLINE_JUDGE
//        freopen("inp.txt", "r", stdin);
//        freopen("out.txt", "w", stdout);
//    #endif
}

const ll mod = 1e9 + 7, maxn = 1e5 + 5, lg = 19, inf = ll(1e9) + 5;

vector<int> adj[maxn], lis[maxn];
vector<pp>  adj2[maxn];
bool vis[maxn], king[maxn];
int cnt_cycle, grp[maxn];

pp dfs(int r, int p){
    pp res = {-1, -1};
    vis[r] = true;
    for(int c: adj[r]) if(c - p){
        if(vis[c]){
            if(res.ff + 1) continue;
            res = {c, cnt_cycle++};
            grp[r] = res.ss;
        }else{
            pp ret = dfs(c, r);
            if(ret.ff + 1){
                assert(res.ff == -1);
                grp[r] = ret.ss;
                res = ret;
            }
        }
    }
    if(res.ff == r) res = {-1, -1};
    return res;
}

ll slv(vector<ll> a){
    if(sz(a) < 3) return a[0];
    int n = sz(a);
    vector<ll> suf(n + 1);
    suf[n] = 1;
    per(i,n-1,0){
        suf[i] = suf[i+1]*a[i]%mod;
    }
    ll cr = 0, mul = a[0];
    rep(i,2,n+1) cr += suf[i], cr %= mod;
    ll res = 0;
    rep(i,0,n-1){
        res = (res + cr*mul)%mod;
        cr = (cr - suf[i + 2] + mod)%mod;
        mul = mul*a[i + 1]%mod;
    }
    return res;
}

ll slv2(vector<ll> a){
    ll res = 0;
    ll cr = 0;
    rep(i,0,sz(a)){
        cr = (cr + 1)*a[i]%mod;
        res = (res + cr)%mod;
    }
    return res;
}

ll dp[maxn], dp2[maxn], ans;
void dfs2(int r, int p){
    for(auto[c, u]: adj2[r]){
        if(c - p){
            king[u] = true;
            dfs2(c, r);
        }
    }
    int pos = 0, ptr = 0;
    for(int u: lis[r]){
        dp2[u] = 1;
        for(int c: adj[u]) if(grp[u] - grp[c] && grp[c] - p){
            dp2[u] = dp2[u]*(dp[c] + 1)%mod;
        }
        if(king[u]) pos = ptr;
        ptr++;
    }
    vector<ll> tmp, tmp2;
    rep(i,pos,sz(lis[r])) tmp.pb(dp2[lis[r][i]]);
    rep(i,0,pos) tmp.pb(dp2[lis[r][i]]);
    rep(i,pos+1,sz(lis[r])) dp[lis[r][i]] = dp2[lis[r][i]], tmp2.pb(dp[lis[r][i]]);
    rep(i,0,pos) dp[lis[r][i]] = dp2[lis[r][i]], tmp2.pb(dp[lis[r][i]]);
    dp[lis[r][pos]] = slv(tmp);
    ans = (ans + dp[lis[r][pos]] + slv2(tmp2))%mod;
}

int main(){ IOS();
    int n, m; cin >> n >> m;
    rep(i,0,m){
        int u, v; cin >> u >> v; u--, v--;
        adj[u].pb(v), adj[v].pb(u);
    }
    fill(grp, grp + n, -1);
    dfs(0, -1);
    rep(i,0,n){
        if(grp[i] == -1) grp[i] = cnt_cycle++;
        lis[grp[i]].pb(i);
    }
    rep(i,0,n){
        for(int c: adj[i]){
            if(grp[i] - grp[c]){
                adj2[grp[i]].pb({grp[c], c});
            }
        }
    }
    king[0] = true;
    dfs2(0, -1);
//    rep(i,0,n){
//        er(i+1, dp[i], dp2[i], king[i], grp[i]);
//    }
//    er(slv2({1, 2, 3, 4}));
    cout << ans << '\n';
    return 0;
}

Subtask #1
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 5 ms 7380 KB Output is correct
6 Correct 4 ms 7332 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Incorrect 3 ms 7380 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 9 ms 8532 KB Output is correct
3 Correct 109 ms 19540 KB Output is correct
4 Correct 104 ms 19544 KB Output is correct
5 Correct 127 ms 19744 KB Output is correct
6 Correct 108 ms 19684 KB Output is correct
7 Correct 123 ms 32632 KB Output is correct
8 Correct 121 ms 27884 KB Output is correct
9 Correct 134 ms 28112 KB Output is correct
10 Correct 93 ms 20692 KB Output is correct
11 Correct 93 ms 19636 KB Output is correct
12 Correct 122 ms 19028 KB Output is correct
13 Correct 118 ms 19076 KB Output is correct
14 Correct 107 ms 25288 KB Output is correct
15 Correct 120 ms 34632 KB Output is correct
16 Correct 122 ms 36324 KB Output is correct
17 Correct 117 ms 19000 KB Output is correct
18 Correct 115 ms 18988 KB Output is correct
19 Correct 112 ms 18972 KB Output is correct
20 Correct 91 ms 20036 KB Output is correct
21 Correct 92 ms 20208 KB Output is correct
22 Correct 88 ms 20044 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 5 ms 7380 KB Output is correct
6 Correct 4 ms 7332 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Incorrect 3 ms 7380 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 5 ms 7380 KB Output is correct
6 Correct 4 ms 7332 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Incorrect 3 ms 7380 KB Output isn't correct
10 Halted 0 ms 0 KB -