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Submission #560079

# Submission time Handle Problem Language Result Execution time Memory
560079 2022-05-11T03:39:35 Z Huy Valley (BOI19_valley) C++17
100 / 100
 244 ms 48340 KB 
#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
/*#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")*/
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ldb = long double;
const int N = (int)5e5;
const int maxN = (int)5e5 + 5;
const ll mod = 1e9 + 7;
//const int mod = 998244353;
const ll infty = 1e17;
const ll logn = 18;
const int base = 311;
const int Block_size = 500;
const int ep = 'a';

int cu[] = {0,0,1,-1};
int cv[] = {-1,1,0,0};

int du[] = {-1,-1,+1,1};
int dv[] = {-1,+1,-1,1};

int cled[] = {6,2,5,5,4,5,6,3,7,6};

void InputFile()
{
    freopen(".inp","r",stdin);
    freopen(".out","w",stdout);
    //freopen("test.out","r",stdin);
}

void FastInput()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int n,s,q,e;
vector<vector<pii>> adj;
int spec[maxN];
int ispec[maxN];
int x[maxN],y[maxN],w[maxN];

void Read()
{
    cin >> n >> s >> q >> e;
    adj.resize(n+1);
    for(int i = 1;i < n;i++)
    {
        cin >> x[i] >> y[i] >> w[i];
        adj[x[i]].push_back({y[i],w[i]});
        adj[y[i]].push_back({x[i],w[i]});
    }
    for(int i = 1;i <= s;i++)
    {
        cin >> spec[i];
        ispec[spec[i]] = 1;
    }
}

int TimeDFS = 0;
int in[maxN];
int jdep[maxN];
int depth[maxN];
int f[30][maxN];
int lca[30][maxN];
int dak[maxN];
int lg[maxN];
int subsz[maxN];

void ScanLog()
{
    lg[1] = 0;
    for(int i = 2;i <= n;i++)
        lg[i] = lg[i/2] + 1;
}

void preDFS(int u,int p)
{
    in[u] = ++TimeDFS;
    subsz[u] = 1;
    if(ispec[u]) dak[u] = 0;
    else dak[u] = infty;
    for(pii x : adj[u])
    {
        if(x.fi == p) continue;
        depth[x.fi] = depth[u] + x.se;
        jdep[x.fi] = jdep[u] + 1;
        preDFS(x.fi,u);
        dak[u] = min(dak[u],dak[x.fi] + x.se);
        subsz[u] += subsz[x.fi];
    }
}

void preDFS2(int u,int p)
{
    for(pii x : adj[u])
    {
        if(x.fi == p) continue;
        lca[0][x.fi] = u;
        f[0][x.fi] = dak[u] - depth[u];
        for(int i = 1;i <= lg[n];i++)
        {
            lca[i][x.fi] = lca[i-1][lca[i-1][x.fi]];
            f[i][x.fi] = min(f[i-1][x.fi],f[i-1][lca[i-1][x.fi]]);
        }
        preDFS2(x.fi,u);
    }
}

int Jump(int u,int p)
{
    int k = jdep[u] - jdep[p];
    int res = dak[u] - depth[u];
    for(int i = lg[n];i >= 0;i--)
    {
        if(k & (1 << i))
        {
            res = min(res,f[i][u]);
            u = lca[i][u];
            k ^= (1 << i);
        }
    }
    return res;
}

void Solve()
{
    ScanLog();
    preDFS(e,0);
    preDFS2(e,0);
    //cout << f[0][3];
    //cout << Jump(5,3);
    while(q--)
    {
        int id,r;
        cin >> id >> r;
        if(jdep[x[id]] < jdep[y[id]]) swap(x[id],y[id]);
        if(in[r] >= in[x[id]] && in[r] <= in[x[id]] + subsz[x[id]] - 1)
        {
            int res = depth[r] + Jump(r,x[id]);
            if(res >= infty) cout <<"oo"<<'\n';
            else cout << res <<'\n';
        }
        else cout <<"escaped"<<'\n';
    }
}

void Debug()
{
    //Main_sub();
    //Naive();
}


int32_t main()
{
    FastInput();
    //InputFile();
    //int sub_type;
    //cin >> sub_type;
    //Sieve();
    int test;
    //cin >> test;
    test = 1;
    while(test--)
        //for(int prc = 1; prc <= test; prc++)
    {
        Read();
        Solve();
        //Debug();
    }
}

Compilation message

valley.cpp: In function 'void InputFile()':
valley.cpp:35:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     freopen(".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~
valley.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen(".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 596 KB Output is correct
2 Correct 3 ms 596 KB Output is correct
3 Correct 3 ms 604 KB Output is correct
4 Correct 3 ms 596 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 596 KB Output is correct
2 Correct 3 ms 596 KB Output is correct
3 Correct 3 ms 604 KB Output is correct
4 Correct 3 ms 596 KB Output is correct
5 Correct 2 ms 816 KB Output is correct
6 Correct 1 ms 852 KB Output is correct
7 Correct 2 ms 852 KB Output is correct
8 Correct 1 ms 852 KB Output is correct
9 Correct 1 ms 852 KB Output is correct
10 Correct 1 ms 852 KB Output is correct
11 Correct 2 ms 852 KB Output is correct
12 Correct 2 ms 856 KB Output is correct
13 Correct 2 ms 860 KB Output is correct
14 Correct 2 ms 844 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 168 ms 44260 KB Output is correct
2 Correct 171 ms 43840 KB Output is correct
3 Correct 179 ms 44104 KB Output is correct
4 Correct 225 ms 46012 KB Output is correct
5 Correct 192 ms 46164 KB Output is correct
6 Correct 244 ms 48204 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 596 KB Output is correct
2 Correct 3 ms 596 KB Output is correct
3 Correct 3 ms 604 KB Output is correct
4 Correct 3 ms 596 KB Output is correct
5 Correct 2 ms 816 KB Output is correct
6 Correct 1 ms 852 KB Output is correct
7 Correct 2 ms 852 KB Output is correct
8 Correct 1 ms 852 KB Output is correct
9 Correct 1 ms 852 KB Output is correct
10 Correct 1 ms 852 KB Output is correct
11 Correct 2 ms 852 KB Output is correct
12 Correct 2 ms 856 KB Output is correct
13 Correct 2 ms 860 KB Output is correct
14 Correct 2 ms 844 KB Output is correct
15 Correct 168 ms 44260 KB Output is correct
16 Correct 171 ms 43840 KB Output is correct
17 Correct 179 ms 44104 KB Output is correct
18 Correct 225 ms 46012 KB Output is correct
19 Correct 192 ms 46164 KB Output is correct
20 Correct 244 ms 48204 KB Output is correct
21 Correct 151 ms 42616 KB Output is correct
22 Correct 151 ms 42400 KB Output is correct
23 Correct 205 ms 42612 KB Output is correct
24 Correct 182 ms 44748 KB Output is correct
25 Correct 216 ms 47680 KB Output is correct
26 Correct 159 ms 42904 KB Output is correct
27 Correct 157 ms 42692 KB Output is correct
28 Correct 168 ms 42920 KB Output is correct
29 Correct 221 ms 44432 KB Output is correct
30 Correct 238 ms 46004 KB Output is correct
31 Correct 190 ms 43372 KB Output is correct
32 Correct 168 ms 43268 KB Output is correct
33 Correct 172 ms 43588 KB Output is correct
34 Correct 230 ms 45480 KB Output is correct
35 Correct 204 ms 48340 KB Output is correct
36 Correct 211 ms 46056 KB Output is correct