Submission #1176254

#	Time	Username	Problem	Language	Result	Execution time	Memory
1176254		Mher777	Portals (BOI14_portals)	C++20	100 / 100	215 ms	51336 KiB

portals

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <array>
#include <string>
#include <algorithm>
#include <cmath>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <utility>
#include <random>
#include <cassert>
#include <fstream>
using namespace std;
mt19937 rnd(time(nullptr));

/* -------------------- Typedefs -------------------- */

typedef int itn;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef float fl;
typedef long double ld;

/* -------------------- Usings -------------------- */

using vi = vector<int>;
using vll = vector<ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

/* -------------------- Defines -------------------- */

#define ff first
#define ss second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mpr make_pair
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define all(x) (x).begin(), (x).end()
#define USACO freopen("feast.in", "r", stdin); freopen("feast.out", "w", stdout);

/* -------------------- Constants -------------------- */

const int dx[8] = { -1, 0, 1, 0, -1, -1, 1, 1 };
const int dy[8] = { 0, -1, 0, 1, -1, 1, -1, 1 };
const int MAX = int(1e9 + 5);
const ll MAXL = ll(1e18) + 5ll;
const ll MOD = ll(1000000007);
const ll MOD2 = ll(998244353);

/* -------------------- Functions -------------------- */

void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

void precision(int x) {
    cout.setf(ios::fixed | ios::showpoint);
    cout.precision(x);
}

ll gcd(ll a, ll b) {
    if (a == 0 || b == 0) return 0;
    while (b) {
        a %= b;
        swap(a, b);
    }
    return a;
}

ll lcm(ll a, ll b) {
    return a / gcd(a, b) * b;
}

ll range_sum(ll a, ll b) {
    if (a > b) return 0ll;
    ll dif = a - 1, cnt = b - a + 1;
    ll ans = ((b - a + 1) * (b - a + 2)) / 2;
    ans += ((b - a + 1) * dif);
    return ans;
}

string dec_to_bin(ll a) {
    string s = "";
    for (ll i = a; i > 0; ) {
        ll k = i % 2;
        i /= 2;
        char c = k + 48;
        s += c;
    }
    if (a == 0) {
        s = "0";
    }
    reverse(all(s));
    return s;
}

ll bin_to_dec(string s) {
    ll num = 0;
    for (int i = 0; i < s.size(); i++) {
        num *= 2ll;
        num += (s[i] - '0');
    }
    return num;
}

ll factorial_by_mod(ll n, ll mod) {
    ll ans = 1;
    ll num;
    for (ll i = 1; i <= n; ++i) {
        num = i % mod;
        ans *= num;
        ans %= mod;
    }
    return ans;
}

bool isPrime(ll a) {
    if (a == 1) return false;
    for (ll i = 2; i * i <= a; i++) {
        if (a % i == 0) return false;
    }
    return true;
}

ll binpow(ll a, ll b) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
        }
        b >>= 1;
        a *= a;
    }
    return ans;
}

ll binpow_by_mod(ll a, ll b, ll mod) {
    if (!a) return 0;
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans *= a;
            ans %= mod;
        }
        b >>= 1;
        a *= a;
        a %= mod;
    }
    return ans;
}

/* -------------------- Solution -------------------- */

const int N = 1005;
char a[N][N];
int wall_dist[N][N], dist[N][N];
pii ver[N][N], nerq[N][N], dzax[N][N], aj[N][N];
bool used[N][N];
int n, m, sx, sy, ex, ey;

void clr_used() {
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            used[i][j] = false;
        }
    }
}

bool is_valid(int x, int y) {
    return (x >= 1 && x <= n && y >= 1 && y <= m);
}

bool wall_adj(int x, int y) {
    if (a[x - 1][y] == '#') return true;
    if (a[x + 1][y] == '#') return true;
    if (a[x][y - 1] == '#') return true;
    if (a[x][y + 1] == '#') return true;
    return false;
}

void direct_nodes() {
    //up
    int x, y;
    for (int j = 1; j <= m; ++j) {
        x = -1, y = -1;
        for (int i = 1; i <= n; ++i) {
            if (a[i][j] == '#') {
                x = -1, y = -1;
            }
            else if (x == -1) {
                x = i, y = j;
            }
            ver[i][j] = { x,y };
        }
    }
    //down
    for (int j = 1; j <= m; ++j) {
        x = -1, y = -1;
        for (int i = n; i >= 1; --i) {
            if (a[i][j] == '#') {
                x = -1, y = -1;
            }
            else if (x == -1) {
                x = i, y = j;
            }
            nerq[i][j] = { x,y };
        }
    }
    //left
    for (int i = 1; i <= n; ++i) {
        x = -1, y = -1;
        for (int j = 1; j <= m; ++j) {
            if (a[i][j] == '#') {
                x = -1, y = -1;
            }
            else if (x == -1) {
                x = i, y = j;
            }
            dzax[i][j] = { x,y };
        }
    }
    //rigth
    for (int i = 1; i <= n; ++i) {
        x = -1, y = -1;
        for (int j = m; j >= 1; --j) {
            if (a[i][j] == '#') {
                x = -1, y = -1;
            }
            else if (x == -1) {
                x = i, y = j;
            }
            aj[i][j] = { x,y };
        }
    }
}

void gna_to_wall(int x, int y, int nx, int ny, queue<pii>& q) {
    if (is_valid(nx, ny) && a[nx][ny] != '#' && !used[nx][ny]) {
        used[nx][ny] = true;
        wall_dist[nx][ny] = wall_dist[x][y] + 1;
        q.push({ nx,ny });
    }
}

void bfs_to_wall(queue<pii> q) {
    while (!q.empty()) {
        int x = q.front().ff, y = q.front().ss;
        q.pop();
        gna_to_wall(x, y, x + 1, y, q);
        gna_to_wall(x, y, x - 1, y, q);
        gna_to_wall(x, y, x, y + 1, q);
        gna_to_wall(x, y, x, y - 1, q);
    }
    clr_used();
}

void gna(int x, int y, int nx, int ny, int val, priority_queue<pair<int, pii>>& q) {
    if (is_valid(nx, ny) && a[nx][ny] != '#' && dist[nx][ny] > dist[x][y] + val + 1) {
        dist[nx][ny] = dist[x][y] + val + 1;
        used[nx][ny] = true;
        q.push({ -dist[nx][ny], { nx, ny } });
    }
}

void dijkstra() {
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            dist[i][j] = MAX;
        }
    }
    priority_queue<pair<int, pii>> q;
    q.push({ 0,{sx,sy} });
    dist[sx][sy] = 0;
    while (!q.empty()) {
        int x = q.top().ss.ff, y = q.top().ss.ss, her = -q.top().ff;
        q.pop();
        if (her > dist[x][y]) continue;
        gna(x, y, x + 1, y, 0, q);
        gna(x, y, x - 1, y, 0, q);
        gna(x, y, x, y + 1, 0, q);
        gna(x, y, x, y - 1, 0, q);
        gna(x, y, ver[x][y].ff, ver[x][y].ss, wall_dist[x][y], q);
        gna(x, y, nerq[x][y].ff, nerq[x][y].ss, wall_dist[x][y], q);
        gna(x, y, dzax[x][y].ff, dzax[x][y].ss, wall_dist[x][y], q);
        gna(x, y, aj[x][y].ff, aj[x][y].ss, wall_dist[x][y], q);
    }
}

void slv() {
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            cin >> a[i][j];
            if (a[i][j] == 'S') {
                sx = i, sy = j;
            }
            if (a[i][j] == 'C') {
                ex = i, ey = j;
            }
        }
    }
    for (int i = 0; i <= n + 1; ++i) {
        for (int j = 0; j <= m + 1; ++j) {
            if (i == 0 || i == n + 1 || j == 0 || j == m + 1) {
                a[i][j] = '#';
            }
        }
    }
    queue<pii> param;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            if (wall_adj(i, j) && a[i][j] != '#') {
                param.push({ i,j });
                used[i][j] = true;
            }
        }
    }
    direct_nodes();
    bfs_to_wall(param);
    dijkstra();
    cout << dist[ex][ey];
}

/*
5 7
S.#....
.#..##.
.......
#.#...#
.#C.##.
*/

void cs() {
    int tstc = 1;
    //cin >> tstc;
    while (tstc--) {
        slv();
    }
}

void precalc() {
    return;
}

int main() {
    fastio();
    precalc();
    //precision(0);
    cs();
    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 19 / 19
• Subtask 5: 30 / 30