Submission #853567

#	Time	Username	Problem	Language	Result	Execution time	Memory
853567		YassirSalama	Race (IOI11_race)	C++17	31 / 100	401 ms	170404 KiB

race

#include "race.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <iomanip>
#include <cmath>
#include <limits>
#include <map>
#include <utility>
#include <cctype>
#include <string>
#include <cstring>
#include <stack>
#include <queue>
#include <functional>
#include <iterator>
using namespace std;
#define OVL(x,s) for(auto y:x) cout<<y<<s; cout<<"\n";
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__);
#define endl "\n"
#define pb push_back
#define F first
#define S second
#define ll long long
#define mod 1000000007
#define all(v) v.begin(),v.end()
const int MAXN=2e5+1;
const int MAXT=110;
const int INF=1e9;
vector<pair<int,int>> v[MAXN];
int n,k;
unordered_map<int,int> mp[MAXN];
vector<vector<int>> arr(MAXN,vector<int>(MAXT,-1));
int ans=INF;
int dfs(int node,int par){
    if(v[node].size()==1&&v[node][0].F==par) return -1;
    mp[node][0]=0;
    arr[node][0]=0;
    for(auto x:v[node]){
        if(x.F==par) continue;
        int a=dfs(x.F,node);
        if(x.S>k) continue;
        if(a==-1){
            int target=k-x.S;
            if(target>=0&&arr[node][target]!=-1){
                ans=min(ans,arr[node][target]+1);
            }
            arr[node][x.S]=1;
            // mp[node][x.S]=1;
        }else{
            // dbg(node);
            for(int i=0;i<MAXT;i++){
                if(i==0) continue;
                int target=k-(i+x.S);
                if(target<0) continue;
                if(arr[x.F][i]==-1) continue;
                // dbg(i,target,arr[node][target],arr[x.F][i]);
                if(arr[node][target]!=-1){
                    ans=min(ans,arr[node][target]+arr[x.F][i]+1);
                }                
            }
            for(int key=0;key<MAXT;key++){
                if(arr[x.F][key]==-1) continue;
                if(key+x.S>=MAXT) continue;
                if(arr[node][key+x.S]!=-1){
                    arr[node][key+x.S]=min(arr[node][key+x.S],arr[x.F][key]+1);
                }else arr[node][key+x.S]=arr[x.F][key]+1;
            }
        }
    }
    // dbg(node,"last");
    for(int i=0;i<MAXT;i++){
        if(arr[node][i]==-1) continue;
        // dbg(i,arr[node][i]);   
    }
    return 1;
}
int best_path(int N, int K, int H[][2], int L[])
{ 
    n=N;
    k=K;
    for(int i=0;i<n-1;i++){
        int a=H[i][0];
        int b=H[i][1];
        int c=L[i];
        v[a].pb({b,c});
        v[b].pb({a,c});
    }
    dfs(0,0);
    if(ans==INF)
        return -1;
    return ans;
}



#ifdef IOI

#define MAX_N 500000

static int N, K;
static int H[MAX_N][2];
static int L[MAX_N];
static int solution;

inline 
void my_assert(int e) {if (!e) abort();}

void read_input()
{
    int i;
    my_assert(2==scanf("%d %d",&N,&K));
    for(i=0; i<N-1; i++)
        my_assert(3==scanf("%d %d %d",&H[i][0],&H[i][1],&L[i]));
    my_assert(1==scanf("%d",&solution));
}

int main()
{
    int ans;
    read_input();
    ans = best_path(N,K,H,L);
    if(ans==solution)
        printf("Correct.\n");
    else
        printf("Incorrect. Returned %d, Expected %d.\n",ans,solution);

    return 0;
}

#endif

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