Submission #691544

#	Time	Username	Problem	Language	Result	Execution time	Memory
691544		saayan007	Race (IOI11_race)	C++17	31 / 100	394 ms	196632 KiB

race

#include "race.h"
#include <bits/stdc++.h>
using namespace std;
#warning notusing64bitint

using ll = int;
using pi = pair<int, int>;
using pl = pair<int, int>;
using vi = vector<int>;
using vl = vector<int>;
using vpi = vector<pair<int, int>>;
using vpl = vector<pair<int, int>>;

#define fur(i, a, b) for(ll i = a; i <= (ll)b; ++i)
#define ruf(i, a, b) for(ll i = a; i >= (ll)b; --i)
#define fr first 
#define sc second
#define mp make_pair
#define pb emplace_back
#define nl "\n"
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

const ll mxn = 2e5L + 1;
ll k;
vpl adj[mxn];
ll dp[mxn][101];
ll sm[mxn][101];
int ans = mxn;

void dfs(ll cur, ll src) {
    for(auto [ch, wt] : adj[cur]) {
        if(ch != src) {
            dfs(ch, cur);
            fur(j, 1, k) {
                if(j - wt >= 0) {
                    if(dp[cur][j] > 1 + dp[ch][j - wt]) {
                        sm[cur][j] = dp[cur][j];
                        dp[cur][j] = 1 + dp[ch][j - wt];
                    } else if(sm[cur][j] > 1 + dp[ch][j - wt]) {
                        sm[cur][j] = 1 + dp[ch][j - wt];
                    }
                }
            }
        }
    }
    dp[cur][0] = 0;
} 

void solve(ll cur, ll src) {
    ans = min(ans, dp[cur][k]);
    for(auto [ch, wt] : adj[cur]) {
        if(ch != src) {
            fur(j, 1, k - 1) {
                if(j - wt < 0)
                    continue;
                ll here = dp[ch][j - wt] + 1;
                ll there = dp[cur][k - j];
                if(k - j - wt >= 0 && dp[ch][k - j - wt] + 1 == there)
                    there = sm[cur][k - j];

                ans = min(ans, here + there);
            }
            solve(ch, cur);
        }
    }
}

int best_path(int N, int K, int H[][2], int L[])
{
    k = K;
    fur(i, 0, N - 2) {
        ++H[i][0]; ++H[i][1];
        adj[H[i][0]].pb(H[i][1], L[i]);
        adj[H[i][1]].pb(H[i][0], L[i]);
    }

    fur(i, 0, N) {
        fur(j, 0, k) {
            dp[i][j] = sm[i][j] = mxn;
        }
    }
    dfs(1, -1);
    // fur(i, 1, N) {
        // fur(j, 0, k) {
            // cout << dp[i][j] << ' ';
        // }
        // cout << nl;
    // }
    // cout << nl;
    // fur(i, 1, N) {
        // fur(j, 0, k) {
            // cout << sm[i][j] << ' ';
        // }
        // cout << nl;
    // }
    // cout << nl;
    solve(1, -1);
    if(ans == mxn)
        ans = -1;
    return ans;
}

Compilation message (stderr)

race.cpp:4:2: warning: #warning notusing64bitint [-Wcpp]
    4 | #warning notusing64bitint
      |  ^~~~~~~

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