Submission #986019

#	Time	Username	Problem	Language	Result	Execution time	Memory
986019		VinhLuu	Maze (JOI23_ho_t3)	C++17	8 / 100	759 ms	643132 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<ll,int,int> tp;
const int N = 6e6 + 5;
const ll oo = 1e14 + 1;
const int mod = 1e9 + 7;
//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<ll> f[N];
vector<int> 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){
    return (ph[u][v] == v ? v : ph[u][v] = row(u, ph[u][v]));
}

int col(int u,int v){
    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});
    ll ans = oo;
    while(!q.empty()){
        ll val;
        int px, py; tie(val, px, py) = q.top();
//        int x = q.front().fi;
//        int y = q.front().se;
        q.pop();
        if(val > f[px][py]) continue;
        if(px == xt && py == yt) ans = min(ans, f[px][py]);

        for(int d = 0; d < 4; d ++){
            int x = px + ha[d];
            int y = py + co[d];
            if(!kt(x, y) || f[x][y] <= f[px][py] + a[x][y]) continue;
            f[x][y] = f[px][py] + a[x][y];
            q.push({f[x][y], x, y});
            if(ph[x][y]){
                ph[x][y]--;
                ph[x][y] = row(x, ph[x][y]);
            }
            if(pc[x][y]){
                pc[x][y]--;
                pc[x][y] = col(pc[x][y], y);
            }
            int l = max(1, x - k + 1), r = min(m, x + k - 1), pl = max(1, y - k + 1), pr = min(n, y + k - 1);
            if(xt >= l && xt <= r && yt >= pl && yt <= pr) ans = min(ans, val + 1);
            if(l - 1 >= 1){
                int lx = l - 1, g = pr;
                while(ph[lx][g] >= pl){
                    g = ph[lx][g];
                    if(f[lx][g] > val + 1 + a[lx][g]) f[lx][g] = val + 1 + a[lx][g], 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 = pr;
                while(ph[lx][g] >= pl){
                    g = ph[lx][g];
                    if(f[lx][g] > val + 1 + a[lx][g]) f[lx][g] = val + 1 + a[lx][g], q.push({f[lx][g], lx, g});
                    if(!ph[lx][g]) break;
                    ph[lx][g]--;
                    ph[lx][g] = row(lx, ph[lx][g]);
                }
            }
            if(pl - 1 >= 1){
                int g = r, ly = pl - 1;
                while(pc[g][ly] >= l){
                    g = pc[g][ly];
                    if(f[g][ly] > val + 1 + a[g][ly]) f[g][ly] = val + 1 + a[g][ly], q.push({f[g][ly], g, ly});
                    if(!pc[g][ly]) break;
                    pc[g][ly]--;
                    pc[g][ly] = col(pc[g][ly], ly);
                }
            }

            if(pr + 1 <= n){
                int g = r, ly = pr + 1;
                while(pc[g][ly] >= l){
                    g = pc[g][ly];
                    if(f[g][ly] > val + 1 + a[g][ly]) f[g][ly] = val + 1 + a[g][ly], 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:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen(task ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen(task ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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