Submission #986005

#	Time	Username	Problem	Language	Result	Execution time	Memory
986005		VinhLuu	Maze (JOI23_ho_t3)	C++17	67 / 100	694 ms	335596 KiB

Main

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
//#define int long long
//#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(lmao) lmao.begin(), lmao.end()

using namespace std;

typedef pair<int,int> pii;
typedef tuple<int,int,int> tp;
const int N = 3e6 + 5;
const int oo = 1e9 + 1;
const int mod = 1e9 + 7;
int block = 316;
//const ll oo = 5e18;

const int ha[4] = {1, -1, 0, 0};
const int co[4] = {0, 0, 1, -1};
const int tx[4] = {1, 1, -1, -1};
const int ty[4] = {1, -1, -1, 1};

int m, n, k, xt, yt, xs, ys;

vector<int> f[N], a[N], ph[N], pc[N];

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

int row(int u,int v){
//    cerr << u << " " << v << " t\n";
    return (ph[u][v] == v ? v : ph[u][v] = row(u, ph[u][v]));
}

int col(int u,int v){
//    cerr << u << " " << v << " " << pc[u][v] << " w\n";
//    if(pc[u][v] == u) return u;
    return (pc[u][v] == u ? u : pc[u][v] = col(pc[u][v], v));
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    #define task "v"
    if(fopen(task ".inp","r")){
        freopen(task ".inp","r",stdin);
        freopen(task ".out","w",stdout);
    }

    cin >> m >> n >> k;
    cin >> xs >> ys >> xt >> yt;
    for(int i = 1; i <= m; i ++){
        string s; cin >> s;
        f[i].pb(oo);
        a[i].pb(0);
        ph[i].pb(0);
        pc[i].pb(0);
        for(int j = 0; j < n; j ++){
            f[i].pb(oo);
            pc[i].pb(0);
            ph[i].pb(j + 1);
            if(s[j] == '.') a[i].pb(0);
            else a[i].pb(1);
        }
        f[i].pb(oo);
        a[i].pb(0);
        ph[i].pb(0);
        pc[i].pb(0);
    }
    for(int i = 1; i <= n + 1; i ++) pc[0].pb(0);
    for(int i = 1; i <= n; i ++){
        for(int j = 1; j <= m; j ++){
            pc[j][i] = j;
        }
    }

//    for(int i = 1; i <= m; i ++){
//        for(int j = 1; j <= n; j ++) cout << a[i][j] << " ";
//        cout << "\n";
//    }
    priority_queue<tp, vector<tp>, greater<tp>> q;
    f[xs][ys] = 0;
    q.push({0, xs, ys});
    int ans = oo;
    while(!q.empty()){
        int val, x, y; tie(val, x, y)  = q.top();
//        int x = q.front().fi;
//        int y = q.front().se;
//        cerr << x << " " << y << " y\n";
        q.pop();
        if(val > f[x][y]) continue;
        if(x == xt && y == yt) ans = min(ans, f[x][y]);
//        cerr << x << " " << y << " " << f[x][y] << " " << val << " ff\n";
//         cerr << pc[5][1] << " uuu\n";

        for(int d = 0; d < 4; d ++){
            int u = x + ha[d];
            int v = y + co[d];
//            cerr << u << " " << v << " t\n";
            if(!kt(u, v) || f[u][v] <= f[x][y] + a[u][v]) continue;
            f[u][v] = f[x][y] + a[u][v];

            q.push({f[u][v], u, v});
            if(ph[u][v]){
                ph[u][v]--;
                ph[u][v] = row(u, ph[u][v]);
            }
            if(pc[u][v]){
                pc[u][v]--;
                pc[u][v] = col(pc[u][v], v);
            }
        }
        int l = max(1, x - k + 1), r = min(m, x + k - 1), a = max(1, y - k + 1), b = min(n, y + k - 1);
        if(xt >= l && xt <= r && yt >= a && yt <= b) ans = min(ans, f[x][y] + 1);
//        for(int d = 0; d < 4; d ++){
//            int u = x + d * (k - 1); u = max(u, 1), u = min(u, m);
//            int v = y + d * (k - 1); v = max(v, 1), v = min(v, n);
//            if(f[u][v] > f[x][y] + 1){
//                q.push({u, v});
//                f[u][v] = f[x][y] + 1;
//                ph[u][v] = le[u][v];
//                ph[u][v] = row(u, ph[u][v]);
//                pc[u][v] = up[u][v];
//                pc[u][v] = col(pc[u][v], v);
//            }
//        }
//        cerr << " done\n";
        if(l - 1 >= 1){
            int lx = l - 1, g = b;
            while(ph[lx][g] >= a){
                g = ph[lx][g];
//                if(x == 4 && y == 4) cerr << lx << " " << g << " " <<  f[lx][g] << " t\n";
                if(f[lx][g] > f[x][y] + 1) f[lx][g] = f[x][y] + 1, q.push({f[lx][g], lx, g});
                if(!ph[lx][g]) break;
                ph[lx][g]--;
                ph[lx][g] = row(lx, ph[lx][g]);
            }
        }
        if(r + 1 <= m){
            int lx = r + 1, g = b;
            while(ph[lx][g] >= a){
                g = ph[lx][g];
//                if(x == 4 && y == 4) cerr << lx << " " << g << " " <<  f[lx][g] << " t\n";
                if(f[lx][g] > f[x][y] + 1) f[lx][g] = f[x][y] + 1, q.push({f[lx][g], lx, g});
                if(!ph[lx][g]) break;
                ph[lx][g]--;
                ph[lx][g] = row(lx, ph[lx][g]);
            }
        }
        if(a - 1 >= 1){
            int g = r, ly = a - 1;
            while(pc[g][ly] >= l){
                g = pc[g][ly];
//                if(x == 4 && y == 4) cerr << g << " " << ly << " " << f[g][ly] << " " << pc[g][ly] << " t\n";
                if(f[g][ly] > f[x][y] + 1) f[g][ly] = f[x][y] + 1, q.push({f[g][ly], g, ly});
                if(!pc[g][ly]) break;
                pc[g][ly]--;
                pc[g][ly] = col(pc[g][ly], ly);
            }
        }

        if(b + 1 <= n){
            int g = r, ly = b + 1;
            while(pc[g][ly] >= l){
                g = pc[g][ly];
                if(f[g][ly] > f[x][y] + 1) f[g][ly] = f[x][y] + 1, q.push({f[g][ly], g, ly});
                if(!pc[g][ly]) break;
                pc[g][ly]--;
                pc[g][ly] = col(pc[g][ly], ly);
            }
        }
    }
    cout << min(ans, f[xt][yt]);
}

/*
6 6 3
5 4
2 1
###.#.
#..#..
...###
###.##
..####
#.#...
*/

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:50:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen(task ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen(task ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 16 / 16
• Subtask 4: 19 / 19
• Subtask 5: 5 / 5
• Subtask 6: 0 / 19
• Subtask 7: 0 / 8
• Subtask 8: 0 / 6