oj.uz

Submission #805742

# Submission time Handle Problem Language Result Execution time Memory
805742 2023-08-03T22:23:38 Z ashcomp LOSTIKS (INOI20_lostiks) C++14
23 / 100
 2000 ms 186160 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
 
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)]);
}

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));
                                //cout<<i<<","<<j<<" \\ "<<V<<","<<U<<","<<W<<" : "<<DIS(ST,W) <<" , "<< DIS(W,V) <<" , "<<DIS(W,U)<<"\n";
                                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 38 ms 94276 KB Output is correct
2 Correct 37 ms 94280 KB Output is correct
3 Correct 167 ms 173236 KB Output is correct
4 Correct 172 ms 173244 KB Output is correct
5 Correct 168 ms 173376 KB Output is correct
6 Correct 170 ms 173212 KB Output is correct
7 Correct 169 ms 173388 KB Output is correct
8 Correct 169 ms 173444 KB Output is correct
9 Correct 168 ms 173668 KB Output is correct
10 Correct 168 ms 173476 KB Output is correct
11 Correct 169 ms 173440 KB Output is correct
12 Correct 167 ms 175984 KB Output is correct
13 Correct 160 ms 175292 KB Output is correct
14 Correct 175 ms 174664 KB Output is correct
15 Correct 169 ms 176188 KB Output is correct
16 Correct 174 ms 177500 KB Output is correct
17 Correct 167 ms 177424 KB Output is correct
18 Correct 168 ms 178172 KB Output is correct
19 Correct 165 ms 184644 KB Output is correct
20 Correct 176 ms 184304 KB Output is correct
21 Correct 169 ms 183996 KB Output is correct
22 Correct 41 ms 94404 KB Output is correct
23 Correct 40 ms 94472 KB Output is correct
24 Correct 39 ms 94508 KB Output is correct
25 Correct 39 ms 94540 KB Output is correct
26 Correct 39 ms 94508 KB Output is correct

Subtask #2
0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 42 ms 94268 KB Output is correct
2 Correct 39 ms 94364 KB Output is correct
3 Correct 41 ms 94540 KB Output is correct
4 Correct 41 ms 94620 KB Output is correct
5 Correct 1932 ms 186096 KB Output is correct
6 Correct 1376 ms 186160 KB Output is correct
7 Execution timed out 2055 ms 174356 KB Time limit exceeded
8 Halted 0 ms 0 KB -

Subtask #3
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 94276 KB Output is correct
2 Correct 37 ms 94280 KB Output is correct
3 Correct 167 ms 173236 KB Output is correct
4 Correct 172 ms 173244 KB Output is correct
5 Correct 168 ms 173376 KB Output is correct
6 Correct 170 ms 173212 KB Output is correct
7 Correct 169 ms 173388 KB Output is correct
8 Correct 169 ms 173444 KB Output is correct
9 Correct 168 ms 173668 KB Output is correct
10 Correct 168 ms 173476 KB Output is correct
11 Correct 169 ms 173440 KB Output is correct
12 Correct 167 ms 175984 KB Output is correct
13 Correct 160 ms 175292 KB Output is correct
14 Correct 175 ms 174664 KB Output is correct
15 Correct 169 ms 176188 KB Output is correct
16 Correct 174 ms 177500 KB Output is correct
17 Correct 167 ms 177424 KB Output is correct
18 Correct 168 ms 178172 KB Output is correct
19 Correct 165 ms 184644 KB Output is correct
20 Correct 176 ms 184304 KB Output is correct
21 Correct 169 ms 183996 KB Output is correct
22 Correct 41 ms 94404 KB Output is correct
23 Correct 40 ms 94472 KB Output is correct
24 Correct 39 ms 94508 KB Output is correct
25 Correct 39 ms 94540 KB Output is correct
26 Correct 39 ms 94508 KB Output is correct
27 Correct 42 ms 94268 KB Output is correct
28 Correct 39 ms 94364 KB Output is correct
29 Correct 41 ms 94540 KB Output is correct
30 Correct 41 ms 94620 KB Output is correct
31 Correct 1932 ms 186096 KB Output is correct
32 Correct 1376 ms 186160 KB Output is correct
33 Execution timed out 2055 ms 174356 KB Time limit exceeded
34 Halted 0 ms 0 KB -