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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#33309 | #4231. Rafting Trip | flower_and_qingyu# | WA | 3ms | 3644kb | C++14 | 2.9kb | 2022-05-31 11:07:13 | 2022-05-31 11:07:15 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
int main() {
// freopen("in.txt", "r", stdin);
int n, m;
cin >> n >> m;
vector<string> a(n);
vector<vector<pair<int, int>>> G(n, vector<pair<int, int>> (m));
vector<vector<vector<pair<int, int>>>> E(n, vector<vector<pair<int, int>>> (m));
vector<vector<int>> deg(n, vector<int> (m));
for(int i = 0; i < n; i ++) cin >> a[i];
map<char, pair<int, int>> mp;
mp['^'] = {-1, 0};
mp['<'] = {0, -1};
mp['>'] = {0, 1};
mp['v'] = {1, 0};
constexpr int d[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
for(int i = 0; i < n; i ++) {
for(int j = 0; j < m; j ++) {
if(mp.count(a[i][j])) {
G[i][j] = {i + mp[a[i][j]].first, j + mp[a[i][j]].second};
if(G[i][j].first >= 0 && G[i][j].first < n && G[i][j].second >= 0 && G[i][j].second < m) {
deg[G[i][j].first][G[i][j].second] ++;
}
}
}
}
queue<pair<int, int>> q;
for(int i = 0; i < n; i ++) for(int j = 0; j < m; j ++) if(mp.count(a[i][j]) && !deg[i][j]) {
q.emplace(i, j);
}
while(!q.empty()) {
auto [x, y] = q.front(); q.pop();
if(!mp.count(a[x][y])) continue;
// cout << x << ' ' << y << ' ' << deg[x][y] << '\n';;
if(G[x][y].first >= 0 && G[x][y].first < n && G[x][y].second >= 0 && G[x][y].second < m) {
E[G[x][y].first][G[x][y].second].emplace_back(x, y);
if(-- deg[G[x][y].first][G[x][y].second] == 0) {
q.emplace(G[x][y]);
}
}
}
vector<vector<int>> vis(n, vector<int> (m)), use(n, vector<int> (m));
int ans = 0, curans = 0;
auto dfs = [&] (auto &self, int x, int y) -> void {
vector<pair<int, int>> del;
for(int c = 0; c < 4; c ++) {
auto dx = x + d[c][0], dy = y + d[c][1];
if(dx >= 0 && dx < n && dy >= 0 && dy < m &&
a[dx][dy] == '#' && !use[dx][dy]) curans ++, use[dx][dy] = 1, del.emplace_back(dx, dy);
}
ans = max(ans, curans);
for(auto [dx, dy] : E[x][y]) {
self(self, dx, dy);
}
for(auto [dx, dy] : del) {
curans --;
use[dx][dy] = 0;
}
};
for(int i = 0; i < n; i ++) {
for(int j = 0; j < m; j ++) if(deg[i][j] && !vis[i][j]) {
int curans = 0;
pair<int, int> u = {i, j};
vector<pair<int, int>> cur, c;
while(!vis[u.first][u.second]) {
vis[u.first][u.second] = 1;
for(int c = 0; c < 4; c ++) {
auto dx = u.first + d[c][0], dy = u.second + d[c][1];
if(dx >= 0 && dx < n && dy >= 0 && dy < m &&
a[dx][dy] == '#' && !use[dx][dy]) cur.emplace_back(dx, dy), curans ++, use[dx][dy] = 1;
}
c.emplace_back(u);
u = G[u.first][u.second];
}
for(auto u : c) {
dfs(dfs, u.first, u.second);
}
for(auto [x, y] : cur) use[x][y] = 0;
}
}
for(int i = 0; i < n; i ++) for(int j = 0; j < m; j ++) {
if(mp.count(a[i][j]) && (G[i][j].first < 0 || G[i][j].first >= n ||
G[i][j].second < 0 || G[i][j].second >= m || !mp.count(a[G[i][j].first][G[i][j].second]))) {
dfs(dfs, i, j);
}
}
cout << ans << '\n';
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 3ms
memory: 3644kb
input:
5 6 v<<<#v v#v<.> >>v<<< ..v##^ #<<<.^
output:
4
result:
ok single line: '4'
Test #2:
score: 0
Accepted
time: 2ms
memory: 3524kb
input:
4 5 >v<<. ^<..# #...# .#>^#
output:
2
result:
ok single line: '2'
Test #3:
score: -100
Wrong Answer
time: 1ms
memory: 3560kb
input:
4 6 >>v#>v ^#>>^v ^<<#v< .#^<<#
output:
0
result:
wrong answer 1st lines differ - expected: '5', found: '0'