#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <random>
using namespace std;
const int N = 3001;
int a[N][N];
int read() {
char c;
cin >> c;
if (c == 'R') return 0;
if (c == 'G') return 1;
if (c == 'W') return 2;
assert(false);
return -1;
}
int n, m;
int ok(int i, int j, int dir) {
if (dir == 0) {
if (i == 0 || i + 1 == n) return 0;
return a[i - 1][j] == 0 && a[i][j] == 1 && a[i + 1][j] == 2;
} else {
if (j == 0 || j + 1 == m) return 0;
return a[i][j - 1] == 0 && a[i][j] == 1 && a[i][j + 1] == 2;
}
}
vector<pair<int, int>> gt(int i, int j, int dir) {
if (dir == 0) {
return {{i - 1, j}, {i, j}, {i + 1, j}};
} else {
return {{i, j - 1}, {i, j}, {i, j + 1}};
}
}
bool inter(vector<pair<int, int>> &x, vector<pair<int, int>> &y) {
for (auto f : x) {
for (auto s : y) {
if (f == s) return 1;
}
}
return 0;
}
vector<vector<int>> g;
int used[N * N];
int clr[N * N];
int mt[N * N];
void dfs(int v, int c, int p) {
clr[v] = c;
used[v] = 1;
for (auto t : g[v]) {
if (t == p) continue;
assert(!used[t]);
if (!used[t]) dfs(t, c ^ 1, cur);
}
}
int sm(int v) {
if (used[v]) return 0;
used[v] = 1;
for (auto t : g[v]) {
if (mt[t] == -1 || sm(mt[t])) {
mt[t] = v;
return 1;
}
}
return 0;
}
void dfs2(int v) {
used[v] = 1;
for (auto t : g[v]) {
if (mt[t] == v) continue;
used[t] = 1;
if (mt[t] != -1 && !used[mt[t]]) dfs2(mt[t]);
}
}
int solve_mathing() {
int f = (int)g.size();
for (int i = 0; i < f; i++) {
if (!used[i]) dfs(i, 0, -1);
}
fill(mt, mt + f, -1);
fill(used, used + f, 0);
for (int i = 0; i < f; i++) {
if (!clr[i]) {
fill(used, used + f, 0);
sm(i);
}
}
fill(used, used + f, 0);
vector<int> ns(f);
for (int i = 0; i < f; i++) {
if (mt[i] != -1) {
ns[mt[i]] = 1;
}
}
for (int i = 0; i < f; i++) {
if (!clr[i] && !ns[i]) {
dfs2(i);
}
}
int ans = 0;
for (int i = 0; i < f; i++) {
ans += (used[i] && !clr[i]);
}
for (int i = 0; i < f; i++) {
ans += (!used[i] && clr[i]);
}
return ans;
}
vector<int> cd[N][N];
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
a[i][j] = read();
}
}
vector<int> tk;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
if (ok(i, j, 0)) {
tk.push_back({i * m + j});
cd[i][j].push_back((int)tk.size() - 1);
}
if (ok(i, j, 1)) {
tk.push_back({i * m + j + n * m});
cd[i][j].push_back((int)tk.size() - 1);
}
}
}
auto get = [&](int x) {
int v = tk[x];
int tp = (v / (n * m));
v %= n * m;
int i = v / m;
int j = v % m;
return gt(i, j, tp);
};
g.resize(tk.size());
for (int i = 0; i < (int)tk.size(); i++) {
int v = (tk[i] % (n * m));
int ri = v / m;
int rj = v % m;
for (int ti = ri - 2; ti <= ri + 2; ti++) {
for (int tj = rj - 2; tj <= rj + 2; tj++) {
if (ti < 0 || tj < 0 || ti >= n || tj >= m) continue;
for (auto j : cd[ti][tj]) {
if (i == j) continue;
vector<pair<int, int>> f = get(i);
vector<pair<int, int>> s = get(j);
if (inter(f, s)) {
g[i].push_back(j);
}
}
}
}
}
cout << solve_mathing() << endl;
}
Compilation message
dango_maker.cpp: In function 'void dfs(int, int, int)':
dango_maker.cpp:80:31: error: 'cur' was not declared in this scope
if (!used[t]) dfs(t, c ^ 1, cur);
^~~
dango_maker.cpp:80:31: note: suggested alternative: 'clr'
if (!used[t]) dfs(t, c ^ 1, cur);
^~~
clr
