Submission #1069942

#	Time	Username	Problem	Language	Result	Execution time	Memory
1069942		vjudge1	Toy (CEOI24_toy)	C++17	100 / 100	242 ms	323408 KiB

Main

#include <bits/stdc++.h>
#define int long long

using namespace std;

const int MAX_N = 1500;

int k, l, h, w;

string grid[MAX_N];
bool intersect[MAX_N][MAX_N];
int up[MAX_N][MAX_N], down[MAX_N][MAX_N], lft[MAX_N][MAX_N], rght[MAX_N][MAX_N];

void func(int x, int y) {
    if(x+1 != h && grid[x+1][y] != 'X' && !intersect[x+1][y]) {
        int min_up = min(up[x+1][y], up[x][y]), min_down = min(down[x+1][y], down[x][y]), sum = min_up + min_down - 1;
        if(sum >= k) {
            intersect[x+1][y] = 1;
            func(x+1, y);
        }
    }
    if(x && grid[x-1][y] != 'X' && !intersect[x-1][y]) {
        int min_up = min(up[x-1][y], up[x][y]), min_down = min(down[x-1][y], down[x][y]), sum = min_up + min_down - 1;
        if(sum >= k) {
            intersect[x-1][y] = 1;
            func(x-1, y);
        }
    }
    if(y+1 != w && grid[x][y+1] != 'X' && !intersect[x][y+1]) {
        int min_left = min(lft[x][y+1], lft[x][y]), min_right = min(rght[x][y+1], rght[x][y]), sum = min_left + min_right - 1;
        if(sum >= l) {
            intersect[x][y+1] = 1;
            func(x, y+1);
        }
    }
    if(y && grid[x][y-1] != 'X' && !intersect[x][y-1]) {
        int min_left = min(lft[x][y-1], lft[x][y]), min_right = min(rght[x][y-1], rght[x][y]), sum = min_left + min_right - 1;
        if(sum >= l) {
            intersect[x][y-1] = 1;
            func(x, y-1);
        }
    }
}

void solve() {
   int x1, y1, x2, y2;
   cin >> w >> h >> k >> l >> x1 >> y1 >> x2 >> y2;
   int ex, ey;
   for(int i=0; i<h; ++i) {
        cin >> grid[i];
        for(int j=0; j<w; ++j) {
            if(grid[i][j] == '*') ex = i, ey = j;
        }
   }
   intersect[y1][x2] = 1;
   for(int i=0; i<h; ++i) {
        up[i][0] = (grid[i][0] == 'X' ? 0 : 1);
        down[i][w-1] = (grid[i][w-1] == 'X' ? 0 : 1);
        for(int j=1; j<w; ++j) up[i][j] = (grid[i][j] == 'X' ? 0 : up[i][j-1] + 1);
        for(int j=w-2; j>=0; --j) down[i][j] = (grid[i][j] == 'X' ? 0 : down[i][j+1] + 1);
   }
   for(int i=0; i<w; ++i) {
        lft[0][i] = (grid[0][i] == 'X' ? 0 : 1);
        rght[h-1][i] = (grid[h-1][i] == 'X' ? 0 : 1);
        for(int j=1; j<h; ++j) lft[j][i] = (grid[j][i] == 'X' ? 0 : lft[j-1][i] + 1);
        for(int j=h-2; j>=0; --j) rght[j][i] = (grid[j][i] == 'X' ? 0 : rght[j+1][i] + 1);
   }
   func(y1, x2);
   cout << (intersect[ex][ey] ? "YES" : "NO") << endl;
}

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

    int t = 1;
    while(t--) solve();
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:69:29: warning: 'ex' may be used uninitialized in this function [-Wmaybe-uninitialized]
   69 |    cout << (intersect[ex][ey] ? "YES" : "NO") << endl;
      |             ~~~~~~~~~~~~~~~~^
Main.cpp:69:29: warning: 'ey' may be used uninitialized in this function [-Wmaybe-uninitialized]

• Subtask 0: 0 / 0
• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 9 / 9
• Subtask 4: 29 / 29
• Subtask 5: 27 / 27