oj.uz

답안 #58480

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
58480 2018-07-18T01:25:07 Z Benq 특수한 그래프 (IZhO13_specialg) C++14
100 / 100
 169 ms 41780 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;


template<int SZ> struct DSU {
    int par[SZ], sz[SZ];
    DSU() {
        F0R(i,SZ) par[i] = i, sz[i] = 1;
    }
    
    int get(int x) { // path compression
    	if (par[x] != x) par[x] = get(par[x]);
    	return par[x];
    }
    
    bool unite(int x, int y) { // union-by-rank
    	x = get(x), y = get(y);
    	if (x == y) return 0;
    	if (sz[x] < sz[y]) swap(x,y);
    	sz[x] += sz[y], par[y] = x;
    	return 1;
    }
};

DSU<MX> D;
int N, M, nex[MX][17], bad[MX], depth[MX];
pi cyc[MX]; // #, pos
int cycsz[MX];
set<int> lef[MX];

vector<array<int,3>> q;
vi ret;

void addEdge(int x) {
    D.unite(x,nex[x][0]);
    if (cyc[x].f) lef[cyc[x].f].erase(cyc[x].s);
}

bool con(int t, int y) {
    assert(t != y);
    int co = cyc[t].f;
    t = cyc[t].s, y = cyc[y].s;
    auto it = lef[co].lb(t);
    if (t > y) {
        if (it != lef[co].end()) return 0;
        it = lef[co].begin();
    }
    return it == lef[co].end() || *it >= y;
}

int dis(int t, int y) {
    int cur = cyc[y].s-cyc[t].s;
    if (cur < 0) cur += cycsz[t];
    return cur;
}

int anc(int x, int d) {
    F0Rd(i,17) if (d&(1<<i)) x = nex[x][i];
    return x;
}

int query(int x, int y) {
    if (D.get(x) != D.get(y)) return -1;
    if (depth[x] >= depth[y]) {
        int t = anc(x,depth[x]-depth[y]);
        if (t == y) return depth[x]-depth[y];
    }
    if (depth[y]) return -1;
    int t = anc(x,depth[x]);
    if (con(t,y)) return depth[x]+dis(t,y);
    return -1;
}

int vis[MX];

void solve(int x) {
    int X = x;
    vi cur;
    while (1) {
        // cout << "AH " << x << " " << X << " " << vis[X] << "\n";
        if (X == 0) return;
        if (vis[X] == 0) {
            vis[X] = x;
        } else if (vis[X] == x) {
            vis[X] += N;
            cur.pb(X);
        } else if (vis[X] == x+N) {
            break;
        } else return;
        X = nex[X][0];
    }
    // cout << "OH " << x << " " << sz(cur) << " " << cur[0] << "\n";
    F0R(i,sz(cur)) {
        cyc[cur[i]] = {x,i};
        cycsz[cur[i]] = sz(cur);
        lef[x].insert(i);
    }
}

int getDepth(int x) {
    if (depth[x]) return depth[x];
    if (x == 0  || vis[x] > N) return 0;
    return depth[x] = getDepth(nex[x][0])+1;
}

void process() {
    // cyc, cycsz, lef
    FOR(i,1,N+1) solve(i);
    FOR(i,1,N+1) if (vis[i] <= N) {
        depth[i] = getDepth(i);
       // cout << "BLAH " << i << " " << depth[i] << "\n";
    }
    /*FOR(i,1,N+1) {
        cout << cyc[i].f << " " << cyc[i].s << " " << cycsz[i] << " " << depth[i] << "\n";
    }*/
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N;
    FOR(i,1,N+1) {
        cin >> nex[i][0];
        if (nex[i][0] == i) nex[i][0] = 0;
    }
    FOR(i,1,17) FOR(j,1,N+1) nex[j][i] = nex[nex[j][i-1]][i-1];
    process();
    cin >> M;
    F0R(i,M) {
        int t; cin >> t;
        if (t == 1) {
            int a; cin >> a; bad[a] = 1;
            q.pb({1,a,0});
        } else {
            int a,b; cin >> a >> b; 
            q.pb({2,a,b});
        }
    }
    FOR(i,1,N+1) if (!bad[i] && nex[i][0]) addEdge(i);
    reverse(all(q));
    for (auto a: q) {
        if (a[0] == 1) addEdge(a[1]);
        else ret.pb(query(a[1],a[2]));
    }
    reverse(all(ret));
    for (int i: ret) cout << i << "\n";
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Subtask #1
100.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 6216 KB Output is correct
2 Correct 8 ms 6560 KB Output is correct
3 Correct 9 ms 6560 KB Output is correct
4 Correct 12 ms 6708 KB Output is correct
5 Correct 12 ms 6716 KB Output is correct
6 Correct 15 ms 7348 KB Output is correct
7 Correct 17 ms 7608 KB Output is correct
8 Correct 16 ms 8016 KB Output is correct
9 Correct 18 ms 8204 KB Output is correct
10 Correct 21 ms 8492 KB Output is correct
11 Correct 142 ms 24704 KB Output is correct
12 Correct 119 ms 24704 KB Output is correct
13 Correct 150 ms 24704 KB Output is correct
14 Correct 107 ms 24704 KB Output is correct
15 Correct 152 ms 25076 KB Output is correct
16 Correct 107 ms 26564 KB Output is correct
17 Correct 138 ms 32396 KB Output is correct
18 Correct 159 ms 34436 KB Output is correct
19 Correct 169 ms 36408 KB Output is correct
20 Correct 138 ms 41780 KB Output is correct