oj.uz

Submission #661141

# Submission time Handle Problem Language Result Execution time Memory
661141 2022-11-24T16:21:39 Z borisAngelov Race (IOI11_race) C++17
0 / 100
 8 ms 14420 KB 
#include <iostream>
#include <utility>
#include <vector>
#include <tuple>
#include <map>
#include "race.h"

using namespace std;

const int maxn = 200005;
const int inf = 1000000000;

int H[maxn][2];
int L[maxn];

int n;
long long k;

vector<pair<int, int>> g[maxn];

long long pathToRoot[maxn];
int depth[maxn];

map<long long, int> info[maxn];

void dfs_precompute(int node, int parent, long long currPath, int currDepth) {
    pathToRoot[node] = currPath;
    depth[node] = currDepth;
    info[node][currPath] = currDepth;

    for (auto [v, w] : g[node]) {
        if (v == parent) continue;

        dfs_precompute(v, node, currPath + w, currDepth + 1);
    }
}

int ans = inf;

void dfs_small_to_large(int node, int parent) {
    long long target = k + 2 * pathToRoot[node];

    for (auto [v, w] : g[node]) {
        if (v == parent) continue;

        dfs_small_to_large(v, node);

        if (info[node].size() < info[v].size()) {
            swap(info[node], info[v]);
        }

        for (auto [dist, edges] : info[v]) {
            if (info[node].find(target - dist) != info[node].end()) {
                ans = min(ans, info[node][target - dist] + edges - 2 * depth[node]);
            }
        }

        for (auto [dist, edges] : info[v]) {
            if (info[node].find(dist) == info[node].end()) {
                info[node].insert({dist, edges});
            } else {
                info[node][dist] = min(info[node][dist], edges);
            }
        }
    }
}

int best_path(int A, int B, int edges[][2], int weights[]) {
    n = A;
    k = B;

    for (int i = 0; i < n; ++i) {
        int u = edges[i][0];
        int v = edges[i][1];
        int w = weights[i];

        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }

    dfs_precompute(0, -1, 0, 0);
    dfs_small_to_large(0, -1);

    if (ans == inf) return -1;
    return ans;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 14420 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 14420 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 14420 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 57.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 14420 KB Output isn't correct
2 Halted 0 ms 0 KB -