Submission #947208

#	Time	Username	Problem	Language	Result	Execution time	Memory
947208		steveonalex	Race (IOI11_race)	C++14	100 / 100	389 ms	102736 KiB

race

#include <bits/stdc++.h>
#include "race.h"
// 

 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2e5 + 69;
const int INF = 1e9 + 69;
int n, k, ans;
vector<pair<int, int>> graph[N];
map<ll, int> dp[N];

void dfs(int u, int p, int h, ll l){
    dp[u][l] = h;
    for(auto v: graph[u]) if (v.first != p){
        dfs(v.first, u, h + 1, l + v.second);
        if (dp[u].size() < dp[v.first].size()) swap(dp[u], dp[v.first]);
        
        for(auto i: dp[v.first]){
            ll _l = k - (i.first - l) + l;
            if (dp[u].count(_l)) minimize(ans, i.second + dp[u][_l] - 2 * h);

        }
        for(auto i: dp[v.first]) {
            if (dp[u].count(i.first)) minimize(dp[u][i.first], i.second);
            else dp[u][i.first] = i.second;
        }
    }
}

int best_path(int _n, int _k, int H[][2], int L[]){
    n = _n; k = _k, ans = INF;
    for(int i= 0; i<=n; ++i) {
        graph[i].clear();
        dp[i].clear();
    }

    for(int i = 0; i<n-1; ++i){
        int u = H[i][0], v = H[i][1], w = L[i];
        graph[u].push_back({v, w});
        graph[v].push_back({u, w});
    }

    dfs(0, 0, 0, 0);
    if (ans == INF) return -1;
    return ans;
}


// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
 
//     return 0;
// }

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