Submission #922041

#	Time	Username	Problem	Language	Result	Execution time	Memory
922041		SUNWOOOOOOOO	Maze (JOI23_ho_t3)	C++17	86 / 100	2029 ms	172452 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using pint = array <int, 2>;
const int INF = 1e9;
vector <vector <int>> ans, G;
vector <vector <pint>> Gelm;
int r, c, n, gno = 0, dx[4] = {0, 0, 1, -1}, dy[4] = {1, -1, 0, 0};
vector <int> Gvst;
vector <string> A;
deque <pint> dq;
pint s, g;

struct segtree { // +1
    int mxX = 1, mxY = 1;
    vector <vector <pint>> node;
    void init(){
        mxX = r;
        mxY = c;
        node.resize(2 * mxX + 1, vector <pint> (2 * mxY + 1, (pint) {INF, INF}));
        for (int i = 0; i < r; i++){
            for (int j = 0; j < c; j++){
                if (A[i][j] != '#') continue;
                node[i + mxX][j + mxY] = {i, j};
            }
        }
        for (int i = mxX; i < 2 * mxX; i++){
            for (int j = mxY - 1; j > 0; j--){
                node[i][j] = min(node[i][2 * j], node[i][2 * j + 1]);
            }
        }
        for (int i = mxX - 1; i > 0; i--){
            for (int j = 1; j < 2 * mxY; j++){
                node[i][j] = min(node[2 * i][j], node[2 * i + 1][j]);
            }
        }
    }
    void update(int x, int y, pint val){
        x++, y++;
        x += mxX - 1, y += mxY - 1;
        node[x][y] = val;
        for (int cy = y / 2; cy > 0; cy /= 2){
            node[x][cy] = min(node[x][2 * cy], node[x][2 * cy + 1]);
        }
        for (int cx = x / 2; cx > 0; cx /= 2){
            for (int cy = y; cy > 0; cy /= 2){
                node[cx][cy] = min(node[cx * 2][cy], node[cx * 2 + 1][cy]);
            }
        }
    }
    pint query(int L1, int R1, int L2, int R2){
        L1++, R1++, L2++, R2++;
        pint ret = {INF, INF};
        for (L1 += mxX - 1, R1 += mxX - 1; L1 <= R1; L1 /= 2, R1 /= 2){
            if (L1 % 2 == 1){
                for (int cL2 = L2 + mxY - 1, cR2 = R2 + mxY - 1; cL2 <= cR2; cL2 /= 2, cR2 /= 2){
                    if (cL2 % 2 == 1) ret = min(ret, node[L1][cL2++]);
                    if (cR2 % 2 == 0) ret = min(ret, node[L1][cR2--]);
                }
                L1++;
            }
            if (R1 % 2 == 0){
                for (int cL2 = L2 + mxY - 1, cR2 = R2 + mxY - 1; cL2 <= cR2; cL2 /= 2, cR2 /= 2){
                    if (cL2 % 2 == 1) ret = min(ret, node[R1][cL2++]);
                    if (cR2 % 2 == 0) ret = min(ret, node[R1][cR2--]);
                }
                R1--;
            }
        }
        return ret;
    }
} tree;

void val_up(int L1, int R1, int L2, int R2, int val){
    L1 = max(L1, 0), R1 = min(R1, r - 1), L2 = max(L2, 0), R2 = min(R2, c - 1);
    while (1){
        pint ret = tree.query(L1, R1, L2, R2);
        if (ret == (pint) {INF, INF}) break;
        ans[ret[0]][ret[1]] = val;
        tree.update(ret[0], ret[1], (pint) {INF, INF});
        dq.push_back(ret);
    }
}

int main()
{
    scanf("%d %d %d", &r, &c, &n);
    A.resize(r);
    ans.resize(r, vector <int> (c, -1));
    G.resize(r, vector <int> (c, -1));
    scanf("%d %d %d %d", &s[0], &s[1], &g[0], &g[1]);
    s[0]--, s[1]--, g[0]--, g[1]--;
    for (int i = 0; i < r; i++) cin >> A[i];

    for (int i = 0; i < r; i++){
        for (int j = 0; j < c; j++){
            if (G[i][j] != -1) continue;
            if (A[i][j] == '#') continue;
            Gelm.push_back(vector <pint> {});
            queue <pint> q;
            G[i][j] = gno;
            Gelm[gno].push_back({i, j});
            q.push({i, j});
            while (!q.empty()){
                pint now = q.front(); q.pop();
                for (int k : {0, 1, 2, 3}){
                    int nx = now[0] + dx[k], ny = now[1] + dy[k];
                    if (nx < 0 || ny < 0 || nx >= r || ny >= c) continue;
                    if (G[nx][ny] != -1) continue;
                    if (A[nx][ny] == '#') continue;
                    G[nx][ny] = gno;
                    Gelm[gno].push_back({nx, ny});
                    q.push({nx, ny});
                }
            }
            gno++;
        }
    }
    Gvst.resize(gno, 0);

    tree.init();
    ans[s[0]][s[1]] = 0;
    dq.push_front(s);
    while (!dq.empty()){
        pint now = dq.front(); dq.pop_front();
        for (int k : {0, 1, 2, 3}){
            int nx = now[0] + dx[k], ny = now[1] + dy[k];
            if (nx < 0 || ny < 0 || nx >= r || ny >= c) continue;
            if (A[nx][ny] == '#' || Gvst[G[nx][ny]] == 1) continue;
            for (pint j : Gelm[G[nx][ny]]){
                if (ans[j[0]][j[1]] == -1){
                    ans[j[0]][j[1]] = ans[now[0]][now[1]];
                    dq.push_front(j);
                }
            }
            Gvst[G[nx][ny]] = 1;
        }
        val_up(now[0] - n, now[0] + n, now[1] - n + 1, now[1] + n - 1, ans[now[0]][now[1]] + 1);
        val_up(now[0] - n + 1, now[0] + n - 1, now[1] + n, now[1] + n, ans[now[0]][now[1]] + 1);
        val_up(now[0] - n + 1, now[0] + n - 1, now[1] - n, now[1] - n, ans[now[0]][now[1]] + 1);
    }

    printf("%d\n", ans[g[0]][g[1]]);

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:86:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |     scanf("%d %d %d", &r, &c, &n);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:90:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     scanf("%d %d %d %d", &s[0], &s[1], &g[0], &g[1]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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