Submission #888447

#	Time	Username	Problem	Language	Result	Execution time	Memory
888447		rahidilbayramli	Race (IOI11_race)	C++17	0 / 100	5 ms	32348 KiB

race

#include"race.h"
#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(v) v.begin(), v.end()
#define pb push_back
#define f first
#define s second
using namespace std;
const int sz = 2e5+5;
vector<pii>g[sz];
int vis[sz], lev[sz], p[30][sz], dis[sz];
void dfs(int node, int par)
{
    for(auto [u, w] : g[node])
    {
        if(u == par)
            continue;
        p[0][u] = node;
        lev[u] = lev[node] + 1;
        dis[u] = dis[node] + w;
        dfs(u, node);
    }
}
int jump(int x, int k)
{
    for(int i = 0; i < 30; i++)
    {
        if((k >> i) & 1)
            x = p[i][x];
    }
    return x;
}
int lca(int x, int y)
{
    if(lev[x] > lev[y])
        swap(x, y);
    int d = lev[y] - lev[x];
    y = jump(y, d);
    if(x == y)
        return x;
    else
    {
        for(int i = 29; i >= 0; i--)
        {
            if(p[i][x] != p[i][y])
            {
                x = p[i][x];
                y = p[i][y];
            }
        }
        return p[0][x];
    }
}
int best_path(int N, int K, int H[][2], int L[])
{
    int n, k, i, j, x, y, z;
    n = N;
    k = K;
    for(i = 0; i < n - 1; i++)
    {
        g[H[i][0]].pb({H[i][1], L[i]});
        g[H[i][1]].pb({H[i][0], L[i]});
    }
    dfs(0, -1);
    for(i = 1; i < 30; i++)
    {
        for(j = 0; j < n; j++)
            p[i][j] = p[i-1][p[i-1][j]];
    }
    int ans = INT_MAX;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < n; j++)
        {
            if(i != j){
            ll a = lca(i, j);
            ll ds = dis[i] + dis[j] - 2 * dis[a];
            if(ds == k)
                ans = min(ans, lev[i] + lev[j] - 2 * lev[a]);
            }
        }
    }
    int f = -1;
    if(ans == LLONG_MAX)
        return f;
    else
        return ans;
}

Compilation message (stderr)

race.cpp: In function 'int best_path(int, int, int (*)[2], int*)':
race.cpp:61:21: warning: unused variable 'x' [-Wunused-variable]
   61 |     int n, k, i, j, x, y, z;
      |                     ^
race.cpp:61:24: warning: unused variable 'y' [-Wunused-variable]
   61 |     int n, k, i, j, x, y, z;
      |                        ^
race.cpp:61:27: warning: unused variable 'z' [-Wunused-variable]
   61 |     int n, k, i, j, x, y, z;
      |                           ^

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57