Submission #1064184

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064184		Theo830	Rail (IOI14_rail)	C++17	56 / 100	277 ms	98480 KiB

rail

#include <bits/stdc++.h>
#include "rail.h"
using namespace std;
typedef int ll;
const ll INF = 1e9+7;
ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ll,ii>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
void findLocation(int n, int first, int location[], int stype[]){
    location[0] = first;
    stype[0] = 1;
    ll dist[n][n];
    f(i,0,n){
        dist[i][i] = 0;
        f(j,i+1,n){
            ll v = getDistance(i,j);
            dist[i][j] = dist[j][i] = v;
        }
    }
    ll mini = INF;
    ll pos;
    f(i,1,n){
        if(mini > dist[0][i]){
            mini = dist[0][i];
            pos = i;
        }
    }
    stype[pos] = 2;
    location[pos] = first + dist[0][pos];
    ll ex = 2;
    bool v[n] = {0};
    v[0] = v[pos] = 1;
    iii dista[n];
    f(i,0,n){
        dista[i] = iii(INF,ii(0,0));
    }
    f(i,0,n){
        if(dista[i].F > dist[0][i]){
            dista[i] = iii(dist[0][i],ii(i,0));
        }
        if(dista[i].F > dist[pos][i]){
            dista[i] = iii(dist[pos][i],ii(i,pos));
        }
    }
    while(ex != n){
        ll prev;
        mini = INF;
        f(i,0,n){
            if(!v[i] && mini > dista[i].F){
                mini = dista[i].F;
                prev = dista[i].S.S;
                pos = dista[i].S.F;
            }
        }
        if(stype[prev] == 1){
            stype[pos] = 2;
            location[pos] = location[prev] + mini;
        }
        else{
            stype[pos] = 1;
            location[pos] = location[prev] - mini;
        }
        v[pos] = 1;
        ex++;
        f(i,0,n){
            if(dista[i].F > dist[pos][i]){
                dista[i] = iii(dist[pos][i],ii(i,pos));
            }
        }
    }
}

Compilation message (stderr)

rail.cpp: In function 'void findLocation(int, int, int*, int*)':
rail.cpp:72:18: warning: 'prev' may be used uninitialized in this function [-Wmaybe-uninitialized]
   72 |         if(stype[prev] == 1){
      |                  ^~~~
rail.cpp:46:40: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   46 |     location[pos] = first + dist[0][pos];
      |                             ~~~~~~~~~~~^

• Subtask 1: 8 / 8
• Subtask 2: 22 / 22
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44