oj.uz

Submission #552586

# Submission time Handle Problem Language Result Execution time Memory
552586 2022-04-23T11:28:49 Z SmolBrain Portals (BOI14_portals) C++17
100 / 100
 559 ms 31768 KB 
// Om Namah Shivaya
// GM in 101 days

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

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

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

int nxtleft[1005][1005], nxtright[1005][1005], nxtup[1005][1005], nxtdown[1005][1005];
bool vis[1005][1005];
int dis[1005][1005], dis2[1005][1005];
int dx[4] = { -1, 1, 0, 0};
int dy[4] = {0, 0, -1, 1};

void solve(int test_case)
{
    // referred to: https://github.com/tmwilliamlin168/CompetitiveProgramming/blob/master/BtOI/14-Portals.cpp and the official editorial code
    // initially got WA cuz i misunderstood the problem statement (more like overlooked a particular case)

    int n, m; cin >> n >> m;
    vector<vector<char>> a(n + 5, vector<char>(m + 5, '#'));
    rep1(i, n) rep1(j, m) cin >> a[i][j];

    rep1(i, n) {
        stack<ll> st;
        rep(j, m + 2) {
            if (a[i][j] == '#') {
                while (!st.empty()) {
                    nxtright[i][st.top()] = j;
                    st.pop();
                }
            }
            else {
                st.push(j);
            }
        }

        while (!st.empty()) st.pop();

        rev(j, m + 1, 0) {
            if (a[i][j] == '#') {
                while (!st.empty()) {
                    nxtleft[i][st.top()] = j;
                    st.pop();
                }
            }
            else {
                st.push(j);
            }
        }
    }

    rep1(j, m) {
        stack<ll> st;

        rep(i, n + 2) {
            if (a[i][j] == '#') {
                while (!st.empty()) {
                    nxtdown[st.top()][j] = i;
                    st.pop();
                }
            }
            else {
                st.push(i);
            }
        }

        while (!st.empty()) st.pop();

        rev(i, n + 1, 0) {
            if (a[i][j] == '#') {
                while (!st.empty()) {
                    nxtup[st.top()][j] = i;
                    st.pop();
                }
            }
            else {
                st.push(i);
            }
        }
    }

    pii start, end;
    rep1(i, n) rep1(j, m) {
        if (a[i][j] == 'S') start = {i, j};
        else if (a[i][j] == 'C') end = {i, j};
    }

    queue<pii> q;
    rep(i, n + 2) rep(j, m + 2) {
        if (a[i][j] != '#') conts;
        q.push({i, j});
        vis[i][j] = 1;
        dis[i][j] = 0;
    }

    while (!q.empty()) {
        auto [i, j] = q.front();
        q.pop();

        rep(x, 4) {
            int i2 = i + dx[x], j2 = j + dy[x];
            if (i2 < 0 or i2 > n + 1 or j2 < 0 or j2 > m + 1) conts;
            if (vis[i2][j2]) conts;

            q.push({i2, j2});
            vis[i2][j2] = 1;
            dis[i2][j2] = dis[i][j] + 1;
        }
    }

    priority_queue< array<int, 3>, vector<array<int, 3>>, greater<array<int, 3>> > pq;
    memset(vis, 0, sizeof vis);
    rep(i, n + 5) rep(j, m + 5) dis2[i][j] = inf1;

    pq.push({0, start.ff, start.ss});
    dis2[start.ff][start.ss] = 0;

    while (!pq.empty()) {
        auto [cost, i, j] = pq.top();
        pq.pop();

        if (vis[i][j]) conts;
        vis[i][j] = 1;

        if (i == end.ff and j == end.ss) {
            cout << cost << endl;
            return;
        }

        rep(x, 4) {
            int i2 = i + dx[x], j2 = j + dy[x];
            if (i2 < 0 or i2 > n + 1 or j2 < 0 or j2 > m + 1) conts;
            if (vis[i2][j2]) conts;
            if (a[i2][j2] == '#') conts;

            if (cost + 1 < dis2[i2][j2]) {
                dis2[i2][j2] = cost + 1;
                pq.push({cost + 1, i2, j2});
            }
        }

        int min_dis_to_wall = dis[i][j];

        vector<pii> cells;
        cells.pb({i, nxtleft[i][j] + 1});
        cells.pb({i, nxtright[i][j] - 1});
        cells.pb({nxtup[i][j] + 1, j});
        cells.pb({nxtdown[i][j] - 1, j});

        for (auto [i2, j2] : cells) {
            int cost2 = cost + min_dis_to_wall;
            if (cost2 < dis2[i2][j2]) {
                dis2[i2][j2] = cost2;
                pq.push({cost2, i2, j2});
            }
        }
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message

portals.cpp: In function 'void usaco(std::string)':
portals.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
portals.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1364 KB Output is correct
2 Correct 1 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1364 KB Output is correct
5 Correct 2 ms 1492 KB Output is correct
6 Correct 1 ms 1492 KB Output is correct
7 Correct 1 ms 1492 KB Output is correct
8 Correct 1 ms 1596 KB Output is correct
9 Correct 1 ms 1364 KB Output is correct
10 Correct 1 ms 1364 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1364 KB Output is correct
2 Correct 1 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1364 KB Output is correct
5 Correct 1 ms 1492 KB Output is correct
6 Correct 1 ms 1492 KB Output is correct
7 Correct 1 ms 1492 KB Output is correct
8 Correct 1 ms 1492 KB Output is correct
9 Correct 2 ms 2516 KB Output is correct
10 Correct 2 ms 2516 KB Output is correct
11 Correct 3 ms 2516 KB Output is correct
12 Correct 2 ms 2516 KB Output is correct
13 Correct 2 ms 2516 KB Output is correct
14 Correct 1 ms 1364 KB Output is correct
15 Correct 2 ms 2556 KB Output is correct
16 Correct 1 ms 1436 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1364 KB Output is correct
2 Correct 1 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1492 KB Output is correct
5 Correct 11 ms 6228 KB Output is correct
6 Correct 16 ms 6344 KB Output is correct
7 Correct 11 ms 6356 KB Output is correct
8 Correct 11 ms 6356 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1364 KB Output is correct
2 Correct 2 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1364 KB Output is correct
5 Correct 1 ms 1492 KB Output is correct
6 Correct 1 ms 1492 KB Output is correct
7 Correct 1 ms 1492 KB Output is correct
8 Correct 1 ms 1492 KB Output is correct
9 Correct 2 ms 2516 KB Output is correct
10 Correct 2 ms 2516 KB Output is correct
11 Correct 2 ms 2468 KB Output is correct
12 Correct 2 ms 2516 KB Output is correct
13 Correct 2 ms 2516 KB Output is correct
14 Correct 10 ms 6284 KB Output is correct
15 Correct 13 ms 6260 KB Output is correct
16 Correct 14 ms 6356 KB Output is correct
17 Correct 11 ms 6264 KB Output is correct
18 Correct 13 ms 6224 KB Output is correct
19 Correct 6 ms 6100 KB Output is correct
20 Correct 10 ms 6100 KB Output is correct
21 Correct 10 ms 6228 KB Output is correct
22 Correct 12 ms 6344 KB Output is correct
23 Correct 11 ms 6236 KB Output is correct
24 Correct 13 ms 6156 KB Output is correct
25 Correct 1 ms 1364 KB Output is correct
26 Correct 2 ms 2516 KB Output is correct
27 Correct 1 ms 1364 KB Output is correct
28 Correct 8 ms 6356 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1364 KB Output is correct
2 Correct 1 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1364 KB Output is correct
5 Correct 1 ms 1492 KB Output is correct
6 Correct 1 ms 1492 KB Output is correct
7 Correct 1 ms 1492 KB Output is correct
8 Correct 1 ms 1492 KB Output is correct
9 Correct 2 ms 2516 KB Output is correct
10 Correct 2 ms 2568 KB Output is correct
11 Correct 2 ms 2516 KB Output is correct
12 Correct 2 ms 2516 KB Output is correct
13 Correct 2 ms 2516 KB Output is correct
14 Correct 11 ms 6312 KB Output is correct
15 Correct 11 ms 6228 KB Output is correct
16 Correct 11 ms 6364 KB Output is correct
17 Correct 13 ms 6228 KB Output is correct
18 Correct 13 ms 6312 KB Output is correct
19 Correct 6 ms 6100 KB Output is correct
20 Correct 11 ms 6100 KB Output is correct
21 Correct 12 ms 6336 KB Output is correct
22 Correct 11 ms 6344 KB Output is correct
23 Correct 12 ms 6344 KB Output is correct
24 Correct 286 ms 29648 KB Output is correct
25 Correct 559 ms 26368 KB Output is correct
26 Correct 115 ms 27024 KB Output is correct
27 Correct 230 ms 27140 KB Output is correct
28 Correct 271 ms 30832 KB Output is correct
29 Correct 233 ms 31712 KB Output is correct
30 Correct 260 ms 31768 KB Output is correct
31 Correct 15 ms 6100 KB Output is correct
32 Correct 365 ms 27024 KB Output is correct
33 Correct 1 ms 1364 KB Output is correct
34 Correct 2 ms 2500 KB Output is correct
35 Correct 235 ms 29068 KB Output is correct
36 Correct 1 ms 1364 KB Output is correct
37 Correct 11 ms 6408 KB Output is correct
38 Correct 159 ms 29968 KB Output is correct
39 Correct 170 ms 31044 KB Output is correct