AOJ2223.cpp

#include <bits/stdc++.h>
using namespace std;

using VS = vector<string>;    using LL = long long;
using VI = vector<int>;       using VVI = vector<VI>;
using PII = pair<int, int>;   using PLL = pair<LL, LL>;
using VL = vector<LL>;        using VVL = vector<VL>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))
#define FOR(i, s, e) for (int(i) = (s); (i) < (e); (i)++)
#define FORR(i, s, e) for (int(i) = (s); (i) > (e); (i)--)
//#pragma GCC optimize ("-O3") 
#ifdef YANG33
#include "mydebug.hpp"
#else
#define DD(x) 
#endif
const int INF = 1e9;                          const LL LINF = 1e16;
const LL MOD = 1000000007;                    const double PI = acos(-1.0);

/* -----  2019/07/10  Problem: AOJ 2223 / Link: https://onlinejudge.u-aizu.ac.jp/challenges/search/volumes/2223  ----- */
#define repi(i,a,b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i,a) repi(i,0,a)
#define pb push_back

int H, W, cnt;
char table[16][16];
const string dir = "URDL";
const int di[] = { -1,0,1,0 }, dj[] = { 0,1,0,-1 };
inline bool in(int i, int j) { return i >= 0 and i < H and j >= 0 and j < W; }
string ans = "";

bool rec(int i, int j, int d, int res) {
	table[i][j] = '.';
	if (!res) return 1;
	rep(k, 3) {
		int nd = (d + k + 3) % 4;
		int ni = i, nj = j;
		ans.pb(dir[nd]);
		while (in(ni, nj) and table[ni][nj] == '.')
			ni += di[nd], nj += dj[nd];
		if (in(ni, nj) and rec(ni, nj, nd, res - 1)) return 1;
		ans.erase(ans.size() - 1);
	}
	table[i][j] = 'o';
	return 0;
}
string solve() {
	rep(i, H)rep(j, W)
		if (dir.find(table[i][j]) != string::npos) {
			rec(i, j, dir.find(table[i][j]), cnt);
			return ans;
		}
	return "";
}

void input() {
	cin >> H >> W;
	rep(i, H) rep(j, W) {
		cin >> table[i][j];
		if (table[i][j] == 'o') cnt++;
	}
}
signed main() {
	input();
	cout << solve() << endl;
	return 0;
}