Submission #330210

#	Time	Username	Problem	Language	Result	Execution time	Memory
330210		Kevin_Zhang_TW	Dango Maker (JOI18_dango_maker)	C++17	33 / 100	8 ms	11372 KiB

dango_maker

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T>
bool chmax(T &a, T b) { return a < b ? (a = b, true) : false; }
template<class T> 
bool chmin(T &a, T b) { return b < a ? (a = b, true) : false; }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U>
void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T>
void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L) == R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
 
const int MAX_N = 3005, MAX_M = MAX_N;//MAX_M = MAX_N * MAX_N / 3 << 1;
char w[MAX_N][MAX_N];
int n, m, a, b, id[MAX_N][MAX_N];
bool valid (char a, char b, char c) { return a == 'R' && b == 'G' && c == 'W'; }
array<int,3> edge[MAX_M];
int ma[MAX_M], vist[MAX_M], deg[MAX_M], lst[MAX_M];
int Time;
void expand(int x, int y) {
	while (true) {
		int u = ma[x];
		ma[x] = y, ma[y] = x;
		if (u == -1) return;
		y = u, x = lst[y];
	}
}
bool dfs(int x) {
	queue<int> q;
	q.push(x);
	vist[x] = Time;
	lst[x] = 0;
	while (q.size()) {
		int x = q.front(); q.pop();
		for (int i = 0;i < deg[x];++i) {
			int u = edge[x][i];
			if (ma[u] == -1)
				return expand(x, u), true;
			lst[u] = x;
			if (exchange(vist[u], Time) != Time)
				q.emplace(ma[u]);
		}
	}
	return false; 
}
int max_clique() {
	b += a;
	memset(ma, -1, sizeof(ma)); 
	int res = b;
 
	for (int i = 1;i <= a;++i)
		if (ma[i] == -1 && (Time = i, dfs(i)))
			--res;
 
	return res; 
}
int solve() {
	for (int i = 1;i <= n;++i)
		for (int j = 1;j <= m;++j) { 
			if (valid(w[i][j-1], w[i][j], w[i][j+1])) 
				id[i][j] = ++a; 
		} 
 
	for (int i = 1;i <= n;++i)
		for (int j = 1;j <= m;++j) { 
			if (valid(w[i-1][j], w[i][j], w[i+1][j])) {
				++b;
				for (int x : {id[i-1][j+1], id[i][j], id[i+1][j-1]}) if (x) {
					edge[x][ deg[x]++ ] = b + a;
				}
			} 
		} 
 
	return max_clique(); 
}
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> m;
	for (int i = 1;i <= n;++i)
		cin >> w[i] + 1;
 
	cout << solve() << '\n';
}

Compilation message (stderr)

dango_maker.cpp: In function 'int32_t main()':
dango_maker.cpp:89:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   89 |   cin >> w[i] + 1;
      |          ~~~~~^~~

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 0 / 67