Submission #463700

#	Time	Username	Problem	Language	Result	Execution time	Memory
463700		gesgha	Awesome Arrowland Adventure (eJOI19_adventure)	C++17	100 / 100	96 ms	3124 KiB

adventure

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define fr(x, l, r) for(int x = l; x <= r; x++)
#define rf(x, l, r) for(int x = l; x >= r; x--)
#define fe(x, y) for(auto& x : y)

#define fi first
#define se second
#define m_p make_pair
#define pb push_back
#define pw(x) (ull(1) << ull(x))
#define all(x) (x).begin(),x.end()
#define sz(x) (int)x.size()
#define mt make_tuple
#define ve vector

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair <ll,ll> pll;
typedef pair <int,int> pii;
typedef pair <ld,ld> pld;

template<typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template<typename T>
bool umn(T& a, T b) { return a > b ? a = b, 1 : 0; }
template<typename T>
bool umx(T& a, T b) { return a < b ? a = b, 1 : 0; }

const ll inf = 1e18;
const int intf = 1e9;
const ll mod = 1e9 + 7;
const ld eps = 0.00000001;
const ll N  = 600;
const char k[4] = {'W', 'S', 'E', 'N'};

char c[N][N];

ll f[N][N];
int n, m;


bool update(int x, int y){
    return (x >= 0 && x < n && y >= 0 && y < m);
}

int main(){
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt","w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#else
//    freopen("mountains.in", "r", stdin);
//    freopen("mountains.out","w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif



    cin >> n >> m;
    fr(i, 0, n - 1){
        fill (f[i], f[i] + m, inf);
    }
    fr(i, 0, n - 1){
        fr(j, 0, m - 1){
            cin >> c[i][j];
        }
    }

    f[0][0] = 0;
    set <pair <ll, pll> > st;

    st.insert({0,{0,0}});

    while(!st.empty()){
        auto it = st.begin();
        ll len = (*it).fi, x = (*it).se.fi, y = (*it).se.se;
        st.erase(it);

        if(c[x][y] == 'X'){
            continue;
        }

        fr(i, 0, 3){
            ll l, _x, _y;
            if(k[i] == c[x][y]){
                l = 0;
            }
            else if(k[(i + 2)%4] == c[x][y]){
                l = 2;
            }
            else if(k[(i + 1)%4] == c[x][y]){
                l = 1;
            }
            else l = 3;
            if(k[i] == 'N'){
                _x = -1;
                _y = 0;
            }
            if(k[i] == 'E'){
                _x = 0;
                _y = 1;
            }
            if(k[i] == 'S'){
                _x = 1;
                _y = 0;
            }
            if(k[i] == 'W'){
                _x = 0;
                _y = -1;
            }
            if(update(x + _x, y + _y)){
//            cout << c[x][y] << " " << k[i] << " " << l << " " << _x << " " << _y<< endl;
                if(f[x + _x][y + _y] > len + l){
                    st.erase({f[x + _x][y + _y], {x + _x, y + _y}});
                    f[x + _x][y + _y] = len + l;
                    st.insert({f[x + _x][y + _y], {x + _x, y + _y}});
                }
            }
        }
    }
    if(f[n - 1][m - 1] != inf)cout << f[n - 1][m - 1] << endl;
    else cout << -1 << endl;
    return 0;
}

Compilation message (stderr)

adventure.cpp: In function 'int main()':
adventure.cpp:123:33: warning: '_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  123 |             if(update(x + _x, y + _y)){
      |                               ~~^~~~
adventure.cpp:123:25: warning: '_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  123 |             if(update(x + _x, y + _y)){
      |                       ~~^~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 50 / 50