oj.uz

Submission #805765

# Submission time Handle Problem Language Result Execution time Memory
805765 2023-08-03T22:53:12 Z ashcomp LOSTIKS (INOI20_lostiks) C++14
23 / 100
 2000 ms 190128 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);
        }
}
 
pair<int,pii> EG[22];
int dp[1<<22][22];
 
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;
                        EG[ps]={w,{v,u}};
                        ps++;
                        
                }
                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[ps]={EN,{EN,n+1}};
        ps++;
        /**/
        pre_LCA();
        for(int i=1; i<=n; i++){
                p[i] = -1;
        }
        dfs(ST);
        for(int i=1; i<(1<<(ps)); i++){
                for(int j=0; j<(ps); j++){
                        dp[i][j] = INF;
                }
                       
                for(int j=0; j<(ps); j++){
                        int x = i ^ (1<<j);
                        if(x>i)continue; 
                        int V=EG[j].S.F , U=EG[j].S.S , W=EG[j].F;
                        
                        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<(ps); f++){
                                int v=EG[f].S.F , u=EG[f].S.S;
                                if(DIS(ST,v)>DIS(ST,u)){
                                        swap(v,u);
                                }
                                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<<(ps)); i++)
        {
                int res = ps-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 94300 KB Output is correct
2 Correct 40 ms 94288 KB Output is correct
3 Correct 176 ms 172076 KB Output is correct
4 Correct 177 ms 172060 KB Output is correct
5 Correct 168 ms 172100 KB Output is correct
6 Correct 174 ms 172068 KB Output is correct
7 Correct 166 ms 172228 KB Output is correct
8 Correct 188 ms 172208 KB Output is correct
9 Correct 171 ms 172532 KB Output is correct
10 Correct 174 ms 172332 KB Output is correct
11 Correct 174 ms 172212 KB Output is correct
12 Correct 162 ms 174652 KB Output is correct
13 Correct 166 ms 174140 KB Output is correct
14 Correct 164 ms 173352 KB Output is correct
15 Correct 180 ms 174940 KB Output is correct
16 Correct 160 ms 176160 KB Output is correct
17 Correct 165 ms 176156 KB Output is correct
18 Correct 169 ms 176956 KB Output is correct
19 Correct 168 ms 183316 KB Output is correct
20 Correct 178 ms 183020 KB Output is correct
21 Correct 170 ms 182652 KB Output is correct
22 Correct 40 ms 94504 KB Output is correct
23 Correct 39 ms 94468 KB Output is correct
24 Correct 41 ms 94528 KB Output is correct
25 Correct 41 ms 94444 KB Output is correct
26 Correct 41 ms 94536 KB Output is correct

Subtask #2
0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 94284 KB Output is correct
2 Correct 40 ms 94320 KB Output is correct
3 Correct 51 ms 94756 KB Output is correct
4 Correct 43 ms 94616 KB Output is correct
5 Execution timed out 2001 ms 190128 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 94300 KB Output is correct
2 Correct 40 ms 94288 KB Output is correct
3 Correct 176 ms 172076 KB Output is correct
4 Correct 177 ms 172060 KB Output is correct
5 Correct 168 ms 172100 KB Output is correct
6 Correct 174 ms 172068 KB Output is correct
7 Correct 166 ms 172228 KB Output is correct
8 Correct 188 ms 172208 KB Output is correct
9 Correct 171 ms 172532 KB Output is correct
10 Correct 174 ms 172332 KB Output is correct
11 Correct 174 ms 172212 KB Output is correct
12 Correct 162 ms 174652 KB Output is correct
13 Correct 166 ms 174140 KB Output is correct
14 Correct 164 ms 173352 KB Output is correct
15 Correct 180 ms 174940 KB Output is correct
16 Correct 160 ms 176160 KB Output is correct
17 Correct 165 ms 176156 KB Output is correct
18 Correct 169 ms 176956 KB Output is correct
19 Correct 168 ms 183316 KB Output is correct
20 Correct 178 ms 183020 KB Output is correct
21 Correct 170 ms 182652 KB Output is correct
22 Correct 40 ms 94504 KB Output is correct
23 Correct 39 ms 94468 KB Output is correct
24 Correct 41 ms 94528 KB Output is correct
25 Correct 41 ms 94444 KB Output is correct
26 Correct 41 ms 94536 KB Output is correct
27 Correct 39 ms 94284 KB Output is correct
28 Correct 40 ms 94320 KB Output is correct
29 Correct 51 ms 94756 KB Output is correct
30 Correct 43 ms 94616 KB Output is correct
31 Execution timed out 2001 ms 190128 KB Time limit exceeded
32 Halted 0 ms 0 KB -