oj.uz

Submission #805747

# Submission time Handle Problem Language Result Execution time Memory
805747 2023-08-03T22:29:06 Z ashcomp LOSTIKS (INOI20_lostiks) C++14
23 / 100
 2000 ms 186188 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
#define all(x) x.begin() , x.end()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define F first
#define S second
#define wall cerr<<"------------------------"<<endl
 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-O2")
 
typedef long long ll;
 
const ll INF = 1e9;
const ll maxn = 1e6 + 10;
const ll mod = 1e9 + 7;
 
int n , m , k , ST , EN;
int h[maxn] , p[maxn] , st[maxn] , en[maxn];
int a[maxn<<1] , rmq[maxn<<1][21] , ps_rmq[maxn<<1][21] , rrmq[maxn<<1][21] , ps_rrmq[maxn<<1][21] , len[maxn<<1];
vector<int> g[maxn] , LSA;
bool mrk[maxn];
void DFS(int v)
{
        mrk[v] = 1;
        LSA.push_back(v);
        st[v] = LSA.size()-1;
        for(auto u : g[v]){
 
                if(mrk[u]==1)continue;
                p[u] = v;
                h[u] = h[v]+1;
                DFS(u);
                LSA.push_back(v);
        }
        en[v] = LSA.size()-1;
        
}
void pre_LCA()
{
        LSA.push_back(0);
        p[ST] = -1;
        h[ST] = 1;
        DFS(ST);
        m = LSA.size()-1;
        //wall;
        for(int i=1; i<=m; i++){
                a[i] = h[LSA[i]];
        }
        for(int j=0; j<21; j++){
                for(int i=1; i<=m; i++){
                        if(j==0){
                                rmq[i][j] = a[i];
                                rrmq[i][j] = a[i];
                                ps_rmq[i][j] = i;
                                ps_rrmq[i][j] = i;
                                continue;
                        }
                        if((i+(1<<j)-1)<=m){
                                rmq[i][j] = rmq[i][j-1];
                                ps_rmq[i][j] = ps_rmq[i][j-1];
                                if(rmq[i][j-1] > rmq[i+(1<<(j-1))][j-1]){
                                        rmq[i][j] = rmq[i+(1<<(j-1))][j-1];
                                        ps_rmq[i][j] = ps_rmq[i+(1<<(j-1))][j-1];
                                }
                        }
                        if((i-(1<<j)+1)>0){
                                rrmq[i][j] = rrmq[i][j-1];
                                ps_rrmq[i][j] = ps_rrmq[i][j-1];
                                if(rrmq[i][j-1] > rrmq[i-(1<<(j-1))][j-1]){
                                        rrmq[i][j] = rrmq[i-(1<<(j-1))][j-1];
                                        ps_rrmq[i][j] = ps_rrmq[i-(1<<(j-1))][j-1];
                                }
                        }
                }
        }
        int PS = 0;
        for(int i=1; i<=m; i++){
                if(((1<<PS)<<1)<=i){
                        PS++;
                }
                len[i] = PS;
        }
}//OK
int LCA(int v , int u)
{
        int l = min(st[v],st[u]) , r=max(st[v],st[u]);
        int ln = len[r-l+1];
        int x = rmq[l][ln] , y = rrmq[r][ln];
        if(x < y){
                int pos = ps_rmq[l][ln];
                return LSA[pos];
        }else{
                int pos = ps_rrmq[r][ln];
                return LSA[pos];
        }
}
int DIS(int v , int u)
{
        return (h[v]+h[u]-h[LCA(v,u)]-h[LCA(v,u)]);
}
//OK

vector<pii> eg[maxn];
bool mark[maxn];
int req[maxn];
map<int,int> MP[maxn]; 
void dfs(int v)
{
        mark[v] = 1;
        for(auto e : eg[v]){
                int u=e.F , w=e.S;
                if(mark[u]==1)continue;
                p[u] = v;
                req[u] = req[v];
                if(w!=0){
                        int x = MP[v][u];
                        req[u] |= (1<<x);
                }
                dfs(u);
        }
}

vector<pair<int,pii>> EG;
int dp[1<<21][21];

int main()
{
        ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
        cin>>n>>ST>>EN;
        int ps = 0;
        for(int i=1; i<n; i++){
                int v,u,w; cin>>v>>u>>w;
                if(w!=0){
                        MP[v][u] = ps;
                        MP[u][v] = ps;
                        ps++;
                        EG.push_back({w,{v,u}});
                }
                eg[v].push_back({u,w});
                eg[u].push_back({v,w});
                g[v].push_back(u);
                g[u].push_back(v);
        }
        eg[EN].push_back({n+1,EN});
        eg[n+1].push_back({EN,EN});
        MP[EN][n+1] = ps;
        MP[EN][n+1] = ps;
        EG.push_back({EN,{EN,n+1}});
        /**/
        pre_LCA();
        for(int i=1; i<=n; i++){
                p[i] = -1;
        }
        dfs(ST);
        for(int i=1; i<(1<<((int)EG.size())); i++){
                for(int j=0; j<((int)EG.size()); j++){
                        dp[i][j] = INF;
                }
                for(int j=0; j<((int)EG.size()); j++){
                        int V=EG[j].S.F , U=EG[j].S.S , W=EG[j].F;
                        int x = i ^ (1<<j);
                        if(x>i)continue;
                        if(req[W]!=(req[W]&x))continue;
                        if(req[V]!=(req[V]&x) && req[U]!=(req[U]&x))continue;
                        if(x==0){
                                dp[i][j] = DIS(ST,W) + min(DIS(W,V),DIS(W,U));
                                continue;
                        }
                        for(int f=0; f<((int)EG.size()); f++){
                                int v=EG[f].S.F , u=EG[f].S.S;
                                int D1=DIS(ST,v) , D2=DIS(ST,u);
                                if(D1>D2){
                                        swap(v,u);
                                        swap(D1,D2);
                                }
                                dp[i][j] = min(dp[i][j] , dp[x][f]+DIS(v,W)+min(DIS(W,V),DIS(W,U)) );
                        }
                }
        }
        int ans = INF;
        for(int i=1; i<(1<<((int)EG.size())); i++)
        {
                int res = EG.size()-1;
                ans = min(dp[i][res],ans);
        }
        if(ans==INF){
                cout<<-1;
                return 0;
        }
        cout<<ans;
        return 0;
}
/*
3
1 3
1 2 3
1 3 2
*/
/*
10
1 10
1 2 0
2 3 0
3 4 0
4 5 2
2 6 4
2 7 0
7 8 5
8 9 6
9 10 0
ans = 15
*/
/**
4
1 4
1 2 0
1 3 2
3 4 1
ans = 4;
*/
/*
5
3 1
1 2 5
2 3 4
3 4 0
4 5 2
ans = 10;
*/

Subtask #1
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 40 ms 94244 KB Output is correct
2 Correct 39 ms 94296 KB Output is correct
3 Correct 187 ms 172048 KB Output is correct
4 Correct 176 ms 171992 KB Output is correct
5 Correct 177 ms 172096 KB Output is correct
6 Correct 172 ms 172000 KB Output is correct
7 Correct 222 ms 172204 KB Output is correct
8 Correct 180 ms 172244 KB Output is correct
9 Correct 180 ms 172468 KB Output is correct
10 Correct 174 ms 172216 KB Output is correct
11 Correct 192 ms 172168 KB Output is correct
12 Correct 177 ms 174672 KB Output is correct
13 Correct 165 ms 174020 KB Output is correct
14 Correct 166 ms 173360 KB Output is correct
15 Correct 174 ms 174908 KB Output is correct
16 Correct 201 ms 176052 KB Output is correct
17 Correct 167 ms 176204 KB Output is correct
18 Correct 171 ms 176944 KB Output is correct
19 Correct 170 ms 183360 KB Output is correct
20 Correct 168 ms 183132 KB Output is correct
21 Correct 197 ms 182780 KB Output is correct
22 Correct 42 ms 94428 KB Output is correct
23 Correct 40 ms 94516 KB Output is correct
24 Correct 40 ms 94408 KB Output is correct
25 Correct 40 ms 94548 KB Output is correct
26 Correct 46 ms 94412 KB Output is correct

Subtask #2
0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 42 ms 94256 KB Output is correct
2 Correct 40 ms 94336 KB Output is correct
3 Correct 68 ms 94540 KB Output is correct
4 Correct 51 ms 94660 KB Output is correct
5 Execution timed out 2040 ms 186188 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #3
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 40 ms 94244 KB Output is correct
2 Correct 39 ms 94296 KB Output is correct
3 Correct 187 ms 172048 KB Output is correct
4 Correct 176 ms 171992 KB Output is correct
5 Correct 177 ms 172096 KB Output is correct
6 Correct 172 ms 172000 KB Output is correct
7 Correct 222 ms 172204 KB Output is correct
8 Correct 180 ms 172244 KB Output is correct
9 Correct 180 ms 172468 KB Output is correct
10 Correct 174 ms 172216 KB Output is correct
11 Correct 192 ms 172168 KB Output is correct
12 Correct 177 ms 174672 KB Output is correct
13 Correct 165 ms 174020 KB Output is correct
14 Correct 166 ms 173360 KB Output is correct
15 Correct 174 ms 174908 KB Output is correct
16 Correct 201 ms 176052 KB Output is correct
17 Correct 167 ms 176204 KB Output is correct
18 Correct 171 ms 176944 KB Output is correct
19 Correct 170 ms 183360 KB Output is correct
20 Correct 168 ms 183132 KB Output is correct
21 Correct 197 ms 182780 KB Output is correct
22 Correct 42 ms 94428 KB Output is correct
23 Correct 40 ms 94516 KB Output is correct
24 Correct 40 ms 94408 KB Output is correct
25 Correct 40 ms 94548 KB Output is correct
26 Correct 46 ms 94412 KB Output is correct
27 Correct 42 ms 94256 KB Output is correct
28 Correct 40 ms 94336 KB Output is correct
29 Correct 68 ms 94540 KB Output is correct
30 Correct 51 ms 94660 KB Output is correct
31 Execution timed out 2040 ms 186188 KB Time limit exceeded
32 Halted 0 ms 0 KB -