Submission #418602

#	Time	Username	Problem	Language	Result	Execution time	Memory
418602		snasibov05	Race (IOI11_race)	C++14	0 / 100	1 ms	332 KiB

race

#include "race.h"
#include <vector>

using namespace std;

#define oo 2000000000
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second

vector<vector<pii>> ed;
vector<vector<vector<int>>> dp;

void dfs(int cur, int pr, int k){
    dp[0][0][cur] = dp[1][0][cur] = 0;
    for (auto [to, dist] : ed[cur]){
        if (to == pr) continue;
        dfs(to, cur, k);
        vector<int> v(k+1, oo);
        for (int i = 1; i <= k; ++i) {
            for (int j = 0; j <= i - dist; ++j) {
                v[i] = min(v[i], dp[1][i-dist-j][to] + dp[1][j][cur] + 1);
            }
        }

        for (int i = 1; i <= k; ++i) {
            //if (i - dist >= 0) dp[1][i][cur] = min(dp[1][i][cur], dp[1][i - dist][to] + 1);
            dp[1][i][cur] = min(dp[1][i][cur], v[i]);
            dp[0][i][cur] = min(min(dp[0][i][cur], dp[1][i][cur]), min(dp[0][i][to], dp[1][i][to]));
        }
    }

}

int best_path(int n, int k, int h[][2], int l[]){
    ed.resize(n);
    dp.resize(2);
    dp.assign(2, vector<vector<int>>(k+1, vector<int>(n, oo)));
    for (int i = 0; i < n - 1; ++i) {
        ed[h[i][0]].pb({h[i][1], l[i]});
        ed[h[i][1]].pb({h[i][0], l[i]});
    }
    dfs(0, -1, k);
    if (dp[0][k][0] == oo) dp[0][k][0] = -1;

    return dp[0][k][0];

}

Compilation message (stderr)

race.cpp: In function 'void dfs(int, int, int)':
race.cpp:17:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |     for (auto [to, dist] : ed[cur]){
      |               ^

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