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| #include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<queue>
using namespace std;
#define MAXN 1006
int ed = 0;
class maxFlow {
public:
typedef long long ll;
std::queue<int> q;
std::vector<int> head, cur, nxt, to, dep;
std::vector<ll> cap;
maxFlow(int _n = 0) { init(_n); }
void init(int _n) {
head.clear();
head.resize(_n + 1, 0);
nxt.resize(2);
to.resize(2);
cap.resize(2);
}
void init() { init(head.size() - 1); }
int add(int u, int v, ll w) {
nxt.push_back(head[u]);
int x = ( head[u] = to.size() );
to.push_back(v);
cap.push_back(w);
return x;
}
int Add(int u, int v, ll w) {
add(u, v, w);
return add(v, u, 0);
}
void del(int x) { cap[x << 1] = cap[x << 1 | 1] = 0; }
bool bfs(int s, int t, int delta) {
dep.clear();
dep.resize(head.size(), -1);
dep[s] = 0;
q.push(s);
while (!q.empty()) {
int u = q.front();
q.pop();
for (int i = head[u]; i; i = nxt[i]) {
int v = to[i];
ll w = cap[i];
if (w >= delta && dep[v] == -1) {
dep[v] = dep[u] + 1;
q.push(v);
}
}
}
return ~dep[t];
}
ll dfs(int u, ll flow, int t, int delta) {
if (dep[u] == dep[t])
return u == t ? flow : 0;
ll out = 0;
for (int& i = cur[u]; i; i = nxt[i]) {
int v = to[i];
ll w = cap[i];
if (w >= delta && dep[v] == dep[u] + 1) {
ll f = dfs(v, std::min(w, flow - out), t, delta);
cap[i] -= f;
cap[i ^ 1] += f;
out += f;
if (out == flow)
return out;
}
}
return out;
}
ll maxflow(int s, int t) {
ll out = 0;
ll maxcap = *max_element(cap.begin(), cap.end());
for (ll delta = 1ll << int(log2(maxcap) + 1e-12); delta; delta >>= 1) {
while (bfs(s, t, delta)) {
cur = head;
out += dfs(s, 0x7fffffffffffffffll, t, delta);
}
}
return out;
}
ll getflow(int x) const { return cap[x << 1 | 1]; }
} G ;
const int dirx[5] = { 0,0,0,1,-1 };
const int diry[5] = { 0,1,-1,0,0 };
int toint[300];
int n , m;
int lr[MAXN][MAXN] , dir[MAXN][MAXN];
char ch[MAXN][MAXN] , chh[MAXN][MAXN];
vector<int> E[MAXN][MAXN];
int main() {
toint['U'] = 0 , toint['R'] = 1 , toint['D'] = 2 , toint['L'] = 3;
cin >> n >> m;
for( int i = 1 ; i <= n ; ++ i )
scanf("%s",ch[i] + 1);
G.init( n * m * 2 );
int s = n * m * 2 - 1 , t = n * m * 2 - 2;
for( int i = 1 ; i <= n ; ++ i )
for( int j = 1 ; j <= m ; ++ j )
if( ch[i][j] == 'L' ) {
int poi = ( i - 1 ) * m + j;
G.Add( s , poi , 1 );
for( int d = 1 ; d <= 4 ; ++ d ) {
int x = i + dirx[d] , y = j + diry[d];
if( x <= n && y <= m && x && y && ch[x][y] == 'R' )
E[i][j].push_back( G.Add( poi , ( x - 1 ) * m + y , 1 ) );
}
} else {
int poi = ( i - 1 ) * m + j;
G.Add( poi , t , 1 );
}
int res = G.maxflow( s , t );
for( int i = 1 ; i <= n ; ++ i ) {
scanf("%s",chh[i] + 1);
}
if( ( n * m ) & 1 || res != n * m / 2 ) {
printf("%d\n",res);
} else {
int resl = 0 , resr = 0;
for( int i = 1 ; i <= n ; ++ i )
for( int j = 1 ; j <= m ; ++ j ) {
resr += toint[chh[i][j]];
}
for( int i = 1 ; i <= n ; ++ i )
for( int j = 1 ; j <= m ; ++ j ) if( ch[i][j] == 'L' ) {
for( int k = 0 ; k < E[i][j].size() ; ++ k ) if( G.cap[E[i][j][k]] ) {
int to = G.to[E[i][j][k] ^ 1];
for( int d = 1 ; d <= 4 ; ++ d ) {
int x = i + dirx[d] , y = j + diry[d];
if( to == ( x - 1 ) * m + y )
if( d == 3 || d == 4 ) resl += 2;
}
}
}
if( ( resl % 4 ) == ( resr % 4 ) ) printf("%d\n",res);
else printf("%d\n",res-1);
}
}
|
