Created
February 27, 2016 08:33
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yukicoder No.348
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#include <iostream> | |
#include <iomanip> | |
#include <vector> | |
#include <algorithm> | |
#include <numeric> | |
#include <functional> | |
#include <cmath> | |
#include <queue> | |
#include <stack> | |
#include <set> | |
#include <map> | |
#include <sstream> | |
#include <string> | |
#define repd(i,a,b) for (int i=(int)(a);i<(int)(b);i++) | |
#define rep(i,n) repd(i,0,n) | |
#define all(x) (x).begin(),(x).end() | |
#define mod 1000000007 | |
#define inf 2000000007 | |
#define mp make_pair | |
#define pb push_back | |
typedef long long ll; | |
using namespace std; | |
template <typename T> | |
inline void output(T a, int p) { | |
if(p) cout << fixed << setprecision(p) << a << "\n"; | |
else cout << a << "\n"; | |
} | |
// end of template | |
// union find | |
class union_find { | |
public: | |
int n; | |
vector<int> parent, rnk, num; | |
union_find(int n) : n(n), parent(n), rnk(n, 0), num(n, 1) {rep(i, n) parent[i] = i; } | |
int root(int x){ return (parent[x] == x) ? x : root(parent[x]); } | |
void unite(int x, int y){ | |
x = root(x); | |
y = root(y); | |
if (x == y) { | |
return; | |
} | |
if (rnk[x] < rnk[y]) { | |
parent[x] = y; | |
num[y] += num[x]; | |
} | |
else{ | |
parent[y] = x; | |
num[x] += num[y]; | |
if (rnk[x] == rnk[y]) { | |
rnk[x]++; | |
} | |
} | |
n--; | |
} | |
bool same(int x, int y) {return root(x) == root(y);} | |
int count(int x){ return num[root(x)]; } | |
}; | |
int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1}; | |
int dy[8] = {0, 1, 0, -1, 1, -1, 1, -1}; | |
int H, W; | |
vector<int> vis; | |
vector<vector<int>> G, T, dp; | |
vector<string> S; | |
void dfs(int pos, int ring, union_find &uf){ | |
vis[pos] = 1; | |
for(int c: G[pos]){ | |
int cx = c % W, cy = c / W; | |
rep(k, ring ? 8 : 4){ | |
if (cx + dx[k] >= 0 && cx + dx[k] < W && cy + dy[k] >= 0 && cy + dy[k] < H) { | |
if (S[cy + dy[k]][cx + dx[k]] == ring ? '.' : 'x' && vis[uf.root((cy + dy[k]) * W + cx + dx[k])] == 0) { | |
T[pos].pb(uf.root((cy + dy[k]) * W + cx + dx[k])); | |
dfs(uf.root((cy + dy[k]) * W + cx + dx[k]), ring ^ 1, uf); | |
} | |
} | |
} | |
} | |
} | |
void dfs_m(int now, union_find &uf){ // 一番浅いところにあるxの輪すべてについてこの操作を行う メモ化再帰 | |
dp[now][1] = uf.count(now); | |
for(int ch: T[now]) for(int chch : T[ch]){ | |
dfs_m(chch, uf); | |
dp[now][0] += max(dp[chch][0], dp[chch][1]); | |
dp[now][1] += dp[chch][0]; | |
} | |
} | |
int main() { | |
cin.tie(0); | |
ios::sync_with_stdio(0); | |
// source code | |
cin >> H >> W; | |
H += 2, W += 2; | |
S.resize(H); | |
S[0] = S[H - 1] = string(W, '.'); | |
rep(i, H - 2){ | |
cin >> S[i + 1]; | |
S[i + 1] = '.' + S[i + 1] + '.'; | |
} | |
union_find uf(H * W); | |
rep(y, H) rep(x, W){ | |
rep(k, S[y][x] == 'x' ? 8 : 4){ | |
if (!(x + dx[k] >= 0 && x + dx[k] < W && y + dy[k] >= 0 && y + dy[k] < H)) continue; | |
if (S[y + dy[k]][x + dx[k]] == S[y][x]){ | |
uf.unite(y * W + x, (y + dy[k]) * W + x + dx[k]); | |
} | |
} | |
} | |
vis.assign(H * W, 0), G.resize(H * W), T.resize(H * W), dp.resize(H * W, vector<int>(2)); | |
rep(i, H * W) G[uf.root(i)].pb(i); | |
dfs(uf.root(0), 0, uf); | |
int ret = 0; | |
for (int x: T[uf.root(0)]) { | |
dfs_m(x, uf); | |
ret += max(dp[x][0], dp[x][1]); | |
} | |
output(ret, 0); | |
return 0; | |
} |
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