oj.uz

Submission #552585

# Submission time Handle Problem Language Result Execution time Memory
552585 2022-04-23T11:28:12 Z SmolBrain Portals (BOI14_portals) C++17
70 / 100
 1000 ms 51068 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] = cost;
            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 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 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 1480 KB Output is correct
7 Correct 1 ms 1492 KB Output is correct
8 Correct 2 ms 1492 KB Output is correct
9 Correct 4 ms 2644 KB Output is correct
10 Correct 3 ms 2644 KB Output is correct
11 Correct 2 ms 2516 KB Output is correct
12 Correct 3 ms 2516 KB Output is correct
13 Correct 3 ms 2516 KB Output is correct
14 Correct 1 ms 1364 KB Output is correct
15 Correct 3 ms 2516 KB Output is correct
16 Correct 1 ms 1364 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 1480 KB Output is correct
4 Correct 1 ms 1492 KB Output is correct
5 Correct 21 ms 6356 KB Output is correct
6 Correct 27 ms 6356 KB Output is correct
7 Correct 24 ms 6388 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 1 ms 1492 KB Output is correct
3 Correct 1 ms 1492 KB Output is correct
4 Correct 1 ms 1376 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 4 ms 2644 KB Output is correct
10 Correct 3 ms 2644 KB Output is correct
11 Correct 2 ms 2512 KB Output is correct
12 Correct 3 ms 2516 KB Output is correct
13 Correct 3 ms 2516 KB Output is correct
14 Correct 20 ms 6376 KB Output is correct
15 Correct 26 ms 6388 KB Output is correct
16 Correct 19 ms 6384 KB Output is correct
17 Correct 23 ms 6228 KB Output is correct
18 Correct 30 ms 6356 KB Output is correct
19 Correct 7 ms 6356 KB Output is correct
20 Correct 22 ms 7840 KB Output is correct
21 Correct 20 ms 6356 KB Output is correct
22 Correct 21 ms 6356 KB Output is correct
23 Correct 25 ms 6356 KB Output is correct
24 Correct 53 ms 6992 KB Output is correct
25 Correct 1 ms 1364 KB Output is correct
26 Correct 3 ms 2504 KB Output is correct
27 Correct 1 ms 1364 KB Output is correct
28 Correct 12 ms 6356 KB Output is correct

Subtask #5
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 1604 KB Output is correct
9 Correct 4 ms 2644 KB Output is correct
10 Correct 3 ms 2644 KB Output is correct
11 Correct 3 ms 2516 KB Output is correct
12 Correct 3 ms 2516 KB Output is correct
13 Correct 3 ms 2516 KB Output is correct
14 Correct 20 ms 6328 KB Output is correct
15 Correct 27 ms 6344 KB Output is correct
16 Correct 20 ms 6304 KB Output is correct
17 Correct 24 ms 6228 KB Output is correct
18 Correct 29 ms 6356 KB Output is correct
19 Correct 7 ms 6336 KB Output is correct
20 Correct 18 ms 7756 KB Output is correct
21 Correct 19 ms 6380 KB Output is correct
22 Correct 21 ms 6356 KB Output is correct
23 Correct 23 ms 6360 KB Output is correct
24 Correct 792 ms 29976 KB Output is correct
25 Execution timed out 1095 ms 51068 KB Time limit exceeded
26 Halted 0 ms 0 KB -