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Submission #1049159

# Submission time Handle Problem Language Result Execution time Memory
1049159 2024-08-08T14:22:31 Z beaconmc Race (IOI11_race) C++14
9 / 100
 2061 ms 159472 KB 
#include "race.h"
#include <bits/stdc++.h>
 
typedef long long ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)

using namespace std;

const ll maxn = 200005;
const ll INF = 1000000000;

vector<vector<ll>> edges[maxn];
ll par[maxn];
ll centpar[maxn];
ll depth[maxn];
ll realdepth[maxn];
ll ancc[maxn][20];
bool visited[maxn];
ll sub[maxn];

ll anc(ll a, ll x){
    if (a==0) return 0;
    if (x==0) return par[a];
    if (ancc[a][x] != -1) return ancc[a][x];
    return ancc[a][x] = anc(anc(a,x-1),x-1);
}

ll lca(ll a, ll b){
    if (depth[a] < depth[b]) swap(a,b);
    FORNEG(i,19,-1) if (depth[anc(a, i)] >= depth[b]) a = anc(a,i);
    if (a==b) return a;
    FORNEG(i,19,-1) if (anc(a,i) != anc(b,i)) a = anc(a,i), b = anc(b,i);
    return par[a];
}

void initdfs(ll a,ll p, ll d, ll dd){
    par[a] = p;
    depth[a] = d;
    realdepth[a] = dd;
    for (auto&i : edges[a]){
        if (i[0] != p) initdfs(i[0], a, d+1, dd+i[1]);
    }
}

ll centroid(ll root, ll a, ll p){
    for (auto&i : edges[a]){
        if (!visited[i[0]] && i[0] != p && sub[i[0]] > sub[root]/2) return centroid(root, i[0], a);
    }
    return a;
}
void dfs(ll a, ll p){
    sub[a] = 1;
    for (auto&i : edges[a]){

        if(i[0] != p && !visited[i[0]]) dfs(i[0], a), sub[a] += sub[i[0]];
    }
}
void build(ll a, ll p){

    dfs(a,p);
    ll cent = centroid(a, a, p);


    centpar[cent] = p;
    visited[cent] = 1;
    for (auto&i : edges[cent]){
        if (!visited[i[0]]) build(i[0], cent);
    }
}

map<ll, pair<array<ll,2>,array<ll,2>>> dists[maxn];

int best_path(int N, int K, int H[][2], int L[])
{
    FOR(i,0,maxn) par[i] = -1, centpar[i] = -1, par[i] -1, depth[i] = -1, realdepth[i] = -1,visited[i] = 0,dists[i].clear(),edges[i].clear();
    FOR(i,0,maxn)FOR(j,0,20) ancc[i][j] = -1;
    
    
    FOR(i,0,N-1){

        edges[H[i][0]].push_back({H[i][1], L[i]});
        edges[H[i][1]].push_back({H[i][0], L[i]});
    }

    
    initdfs(0,-1,0,0);
    dfs(0,-1);

    build(0,-1);



    

    FOR(i,0,N){
        ll temp = centpar[i];
        ll prev = i;

        while (temp != -1){
            ll idk = lca(temp,i);
            ll cur = depth[temp] + depth[i] - depth[idk]*2;

           
            ll dist = realdepth[temp] + realdepth[i] - realdepth[idk]*2;
          if (dist > 1000) break;

            if (dists[temp].count(dist) == 0) dists[temp][dist] = make_pair(array<ll,2>{cur, prev}, array<ll,2>{INF, INF});
            else{
                array<ll,2> a,b;
                a = dists[temp][dist].first;
                b = dists[temp][dist].second;

                if (a[1] == prev){
                    a[0] = min(a[0], cur);
                }else if (b[1] == prev){
                    b[0] = min(b[0], cur);
                }else{
                    if (cur <= a[0]) b = a, a = {cur, prev};
                    else if (cur <= b[0]) b = {cur, prev};
                }
                if (a[0] > b[0]) swap(a,b);
                dists[temp][dist] = make_pair(a,b);
            }
            prev = temp;
            temp = centpar[temp];

        }
    }
    ll ans = INF;
    FOR(i,0,N){
        for (auto&k : dists[i]){
            ll req = K-k.first;
            if (req == 0) ans = min(ans, k.second.first[0]);


            if (dists[i].count(req)==0) continue;
            if (req == k.first){

                ans = min(ans, k.second.first[0]+k.second.second[0]);
            }
            else{

                // cout << k.second.first[0] << " " << k.second.first[1] << endl;
                // cout << dists[i][req].first[0] << " " << dists[i][req].first[1] << endl;

                if (k.second.first[1] != dists[i][req].first[1]) ans = min(ans, k.second.first[0] + dists[i][req].first[0]);
                if (k.second.first[1] != dists[i][req].second[1]) ans = min(ans, k.second.first[0] + dists[i][req].second[0]);
                if (k.second.second[1] != dists[i][req].first[1]) ans = min(ans, k.second.second[0] + dists[i][req].first[0]);
                if (k.second.second[1] != dists[i][req].second[1]) ans = min(ans, k.second.second[0] + dists[i][req].second[0]);
            }
        }
    }

    if (ans >= INF) return -1;
    else return ans;

}

Compilation message

race.cpp: In function 'int best_path(int, int, int (*)[2], int*)':
race.cpp:76:56: warning: right operand of comma operator has no effect [-Wunused-value]
   76 |     FOR(i,0,maxn) par[i] = -1, centpar[i] = -1, par[i] -1, depth[i] = -1, realdepth[i] = -1,visited[i] = 0,dists[i].clear(),edges[i].clear();
      |                                                 ~~~~~~~^~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 57432 KB Output is correct
2 Correct 8 ms 57432 KB Output is correct
3 Correct 6 ms 57436 KB Output is correct
4 Correct 8 ms 57436 KB Output is correct
5 Correct 8 ms 57436 KB Output is correct
6 Correct 8 ms 57436 KB Output is correct
7 Correct 8 ms 57532 KB Output is correct
8 Correct 8 ms 57436 KB Output is correct
9 Correct 7 ms 57436 KB Output is correct
10 Correct 7 ms 57436 KB Output is correct
11 Correct 8 ms 57436 KB Output is correct
12 Correct 7 ms 57416 KB Output is correct
13 Correct 6 ms 57492 KB Output is correct
14 Correct 8 ms 57436 KB Output is correct
15 Correct 6 ms 57436 KB Output is correct
16 Correct 7 ms 57436 KB Output is correct
17 Correct 7 ms 57532 KB Output is correct
18 Correct 7 ms 57432 KB Output is correct

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 57432 KB Output is correct
2 Correct 8 ms 57432 KB Output is correct
3 Correct 6 ms 57436 KB Output is correct
4 Correct 8 ms 57436 KB Output is correct
5 Correct 8 ms 57436 KB Output is correct
6 Correct 8 ms 57436 KB Output is correct
7 Correct 8 ms 57532 KB Output is correct
8 Correct 8 ms 57436 KB Output is correct
9 Correct 7 ms 57436 KB Output is correct
10 Correct 7 ms 57436 KB Output is correct
11 Correct 8 ms 57436 KB Output is correct
12 Correct 7 ms 57416 KB Output is correct
13 Correct 6 ms 57492 KB Output is correct
14 Correct 8 ms 57436 KB Output is correct
15 Correct 6 ms 57436 KB Output is correct
16 Correct 7 ms 57436 KB Output is correct
17 Correct 7 ms 57532 KB Output is correct
18 Correct 7 ms 57432 KB Output is correct
19 Correct 7 ms 57436 KB Output is correct
20 Correct 7 ms 57436 KB Output is correct
21 Correct 8 ms 57856 KB Output is correct
22 Incorrect 7 ms 57436 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 57432 KB Output is correct
2 Correct 8 ms 57432 KB Output is correct
3 Correct 6 ms 57436 KB Output is correct
4 Correct 8 ms 57436 KB Output is correct
5 Correct 8 ms 57436 KB Output is correct
6 Correct 8 ms 57436 KB Output is correct
7 Correct 8 ms 57532 KB Output is correct
8 Correct 8 ms 57436 KB Output is correct
9 Correct 7 ms 57436 KB Output is correct
10 Correct 7 ms 57436 KB Output is correct
11 Correct 8 ms 57436 KB Output is correct
12 Correct 7 ms 57416 KB Output is correct
13 Correct 6 ms 57492 KB Output is correct
14 Correct 8 ms 57436 KB Output is correct
15 Correct 6 ms 57436 KB Output is correct
16 Correct 7 ms 57436 KB Output is correct
17 Correct 7 ms 57532 KB Output is correct
18 Correct 7 ms 57432 KB Output is correct
19 Correct 407 ms 94624 KB Output is correct
20 Correct 415 ms 94800 KB Output is correct
21 Correct 351 ms 93264 KB Output is correct
22 Correct 352 ms 91476 KB Output is correct
23 Correct 784 ms 126036 KB Output is correct
24 Correct 279 ms 88904 KB Output is correct
25 Correct 623 ms 86864 KB Output is correct
26 Correct 207 ms 83796 KB Output is correct
27 Correct 404 ms 134736 KB Output is correct
28 Correct 910 ms 159472 KB Output is correct
29 Correct 973 ms 157176 KB Output is correct
30 Correct 415 ms 137768 KB Output is correct
31 Correct 413 ms 137652 KB Output is correct
32 Correct 846 ms 131412 KB Output is correct
33 Correct 2061 ms 153168 KB Output is correct
34 Incorrect 286 ms 88404 KB Output isn't correct
35 Halted 0 ms 0 KB -

Subtask #4
0 / 57.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 57432 KB Output is correct
2 Correct 8 ms 57432 KB Output is correct
3 Correct 6 ms 57436 KB Output is correct
4 Correct 8 ms 57436 KB Output is correct
5 Correct 8 ms 57436 KB Output is correct
6 Correct 8 ms 57436 KB Output is correct
7 Correct 8 ms 57532 KB Output is correct
8 Correct 8 ms 57436 KB Output is correct
9 Correct 7 ms 57436 KB Output is correct
10 Correct 7 ms 57436 KB Output is correct
11 Correct 8 ms 57436 KB Output is correct
12 Correct 7 ms 57416 KB Output is correct
13 Correct 6 ms 57492 KB Output is correct
14 Correct 8 ms 57436 KB Output is correct
15 Correct 6 ms 57436 KB Output is correct
16 Correct 7 ms 57436 KB Output is correct
17 Correct 7 ms 57532 KB Output is correct
18 Correct 7 ms 57432 KB Output is correct
19 Correct 7 ms 57436 KB Output is correct
20 Correct 7 ms 57436 KB Output is correct
21 Correct 8 ms 57856 KB Output is correct
22 Incorrect 7 ms 57436 KB Output isn't correct
23 Halted 0 ms 0 KB -