Submission

PPPP-PPP

Score: 91

User: Dormon

Problemset: Sirabyrinth 3

Language: cpp

Time: 0.004 second

Submitted On: 2024-12-02 12:32:38

#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>

#define debug(...) Debug(#__VA_ARGS__, __VA_ARGS__)
using namespace std;

template<typename T>
typename std::enable_if<std::is_integral<T>::value>::type
Debug(const char* name, T value) {
    std::cout << name << " : " << value << '\n';
}

template<typename T, typename... Args>
typename std::enable_if<std::is_integral<T>::value>::type
Debug(const char* names, T value, Args... args) {
    const char* comma = strchr(names, ',');
    std::cout.write(names, comma - names) << " : " << value << " | ";
    Debug(comma + 1, args...);
}

struct heap{
    int i, j, w;
    bool operator < (const heap &o) const {
        return w > o.w;
    }
};

vector<pair<int, int>> dir = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};

void solve(){
    int n, m;
    cin >> n >> m;
    vector<string> grid(n+2);
    vector<vector<int>> dist(n+2, vector<int>(m+2, 1e9));
    for (int i = 1;i <= n;i++){
        cin >> grid[i];
        grid[i] = '.' + grid[i] + '.';
    }

    priority_queue<heap> pq;
    for (int i = 0;i < n;i++){
        pq.push({i, 0, 0});
        pq.push({i, m+1, 0});
    }
    for (int i = 0;i < n;i++){
        pq.push({0, i, 0});
        pq.push({n+1, i, 0});
    }

    auto invalid = [&](int i, int j) -> bool {
        return i < 1 || i > n || j < 1 || j > m;
    };

    while (!pq.empty()){
        auto [i, j, w] = pq.top(); pq.pop();
        if (w >= dist[i][j]) continue;
        dist[i][j] = w;
        for (auto [di, dj]:dir){
            if (invalid(i+di, j+dj)) continue;
            int ww = (grid[i+di][j+dj] == '#');
            pq.push({i+di, j+dj, w+ww});
        }
    }
    for (int i = 1;i <= n;i++)
        for (int j = 1;j <= m;j++)
            if (grid[i][j] == 'S'){
                cout << dist[i][j] << '\n';
                return ;
            }
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    int q = 1; 
    //cin >> q;
    while (q--){
        solve();
    }
}