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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#244276 | #7699. Pearls | SolitaryDream | WA | 0ms | 3624kb | C++17 | 2.0kb | 2023-11-08 22:35:36 | 2023-11-08 22:35:37 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int N = 65;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
string d2ch = "NESW";
vector<int> order = {1, 0, 2, 3};
int k, n, m;
string s;
int sx, sy;
string ans;
int ty[N];
int vis[N][N], px[N], py[N];
inline int GetDir(int x, int y, int u, int v) {
if (x == u) return v < y ? 1 : 3;
return u < x ? 0 : 2;
}
inline int Check(int ps) {
// int d1 = GetDir(px[ps], py[ps], px[(ps + 1) % k], py[(ps + 1) % k]);
// int d2 = GetDir(px[ps], py[ps], px[(ps - 1 + k) % k], py[(ps - 1 + k) % k]);
if (s[ps] == '.') return !ty[ps];
if (s[ps] == 'W') return ty[(ps + 1) % k] || ty[(ps + k - 1) % k];
return ty[ps] && !ty[(ps + 1) % k] && !ty[(ps + k - 1) % k];
}
inline void Dfs(int x, int y, int ps) {
px[ps] = x; py[ps] = y;
if (ps == k - 1) {
// cerr << ans << endl;
// cerr << x << ' ' << y << endl;
if (abs(x - sx) + abs(y - sy) != 1) return;
ans[ps] = d2ch[GetDir(x, y, sx, sy)];
ty[ps] = ((GetDir(x, y, sx, sy) - GetDir(x, y, px[ps - 1], py[ps - 1]) + 4) % 4 & 1);
ty[0] = ((GetDir(px[0], py[0], px[1], py[1]) - GetDir(px[0], px[0], x, y) + 4) % 4 & 1);
if (Check(ps) && Check(ps - 1) && Check(0) && Check(1)) {
cout << ans << endl;
exit(0);
}
return;
}
vis[x][y] = 1;
for (auto d : order) {
int nx = x + dx[d], ny = y + dy[d];
if (nx > 0 && ny > 0 && nx <= n && ny <= m && !vis[nx][ny]) {
ans[ps] = d2ch[d];
if (ps >= 1) ty[ps] = (d - GetDir(x, y, px[ps - 1], py[ps - 1]) + 4) % 4 & 1;
if (ps >= 3 && !Check(ps - 1)) continue;
Dfs(nx, ny, ps + 1);
}
}
vis[x][y] = 0;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> k >> n >> m;
cin >> s;
cin >> sx >> sy;
ans.resize(k);
Dfs(sx, sy, 0);
cout << "impossible\n";
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3624kb
input:
16 5 6 B.B.B.BW.WB..WB. 3 1
output:
EENNEESSSSWWWWNN
result:
ok single line: 'EENNEESSSSWWWWNN'
Test #2:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
6 5 5 W..B.B 3 3
output:
impossible
result:
ok single line: 'impossible'
Test #3:
score: -100
Wrong Answer
time: 0ms
memory: 3580kb
input:
8 5 5 B.B.B.B. 5 5
output:
NNWWSSEW
result:
wrong answer 1st lines differ - expected: 'NNWWSSEE', found: 'NNWWSSEW'