Submission #1090190

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090190		ShaShi	Portals (BOI14_portals)	C++17	100 / 100	504 ms	158800 KiB

portals

#include <bits/stdc++.h>
 
// #define int long long
 
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
 
#define F first 
#define S second
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
#define kill(x) cout << x << "\n", exit(0);
#define pii pair<int, int>
#define endl "\n"
 
 
 
using namespace std;
typedef long long ll;
// typedef __int128_t lll;
typedef long double ld;
 
const int MAXN = (int)1e3 + 7;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9 + 7;
 
 
int n, m, k, tmp, t, tmp2, tmp3, tmp4, u, v, w, flag, q, ans, flag2;
int arr[MAXN][MAXN], dis[MAXN][MAXN], dp[4][MAXN][MAXN]; pii start, final;
vector<pair<pii, int>> adj[MAXN][MAXN]; char ch;
priority_queue<pair<int, pii>, vector<pair<int, pii>>, greater<pair<int, pii>>> pq;


inline void add_edge(pii x, pii y, int w=1) { adj[x.F][x.S].pb({y, w}); }
 
 
int32_t main() {
    #ifdef LOCAL
    freopen("inp.in", "r", stdin);
    freopen("res.out", "w", stdout);
    #else
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #endif

    cin >> n >> m;

    for (int i=1; i<=n; i++) {
        for (int j=1; j<=m; j++) {
            cin >> ch;

            if (ch == 'C') final = {i, j}, arr[i][j] = 1;
            else if (ch == 'S') start = {i, j}, arr[i][j] = 1;
            else if (ch == '.') arr[i][j] = 1;

            add_edge({i, j}, {i+1, j}); add_edge({i, j}, {i-1, j});
            add_edge({i, j}, {i, j+1}); add_edge({i, j}, {i, j-1});
        }
    }


    for (int i=1; i<=n; i++) {
        for (int j=1; j<=m; j++) {
            if (!arr[i][j]) dp[0][i][j] = 0;
            else dp[0][i][j] = dp[0][i-1][j]+1;

            if (!arr[i][j]) dp[3][i][j] = 0;
            else dp[3][i][j] = dp[3][i][j-1]+1;
        }
    }

    for (int i=n; i>=1; i--) {
        for (int j=m; j>=1; j--) {
            if (!arr[i][j]) dp[1][i][j] = 0;
            else dp[1][i][j] = dp[1][i][j+1]+1;

            if (!arr[i][j]) dp[2][i][j] = 0;
            else dp[2][i][j] = dp[2][i+1][j]+1;
        }
    }


    for (int i=1; i<=n; i++) {
        for (int j=1; j<=m; j++) {
            if (!arr[i][j]) continue;

            tmp = min({dp[0][i][j], dp[1][i][j], dp[2][i][j], dp[3][i][j]});

            add_edge({i, j}, {i-dp[0][i][j]+1, j}, tmp);
            add_edge({i, j}, {i+dp[2][i][j]-1, j}, tmp);
            add_edge({i, j}, {i, j-dp[3][i][j]+1}, tmp);
            add_edge({i, j}, {i, j+dp[1][i][j]-1}, tmp);
        }
    }

    memset(dis, 1, sizeof(dis));

    dis[start.F][start.S] = 0; pq.push({0, start});

    while (pq.size()) {
        auto cur = pq.top(); pq.pop();

        if (dis[cur.S.F][cur.S.S] != cur.F) continue;

        pii u = cur.S;

        if (u == final) kill(cur.F);

        for (auto cur:adj[u.F][u.S]) {
            if (arr[cur.F.F][cur.F.S] && dis[cur.F.F][cur.F.S] > dis[u.F][u.S]+cur.S) {
                dis[cur.F.F][cur.F.S] = dis[u.F][u.S]+cur.S;
                pq.push({dis[cur.F.F][cur.F.S], cur.F});
            }
        }
    }


 
    return 0;
}

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