백준 1189번 컴백홈 C++

출처 : https://www.acmicpc.net/problem/1189

 

백트래킹을 이용하였다.

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <limits.h>

using namespace std;
using ll = long long;

int r, c, k;
int ans = 0;
pair<int, int> start, target;

int dRow[4] = { -1,0,1,0 };
int dCol[4] = { 0,1,0,-1 };

vector<vector<char>> board(5, vector<char>(5));
vector<vector<bool>> visited(5, vector<bool>(5, false));

void BT(int dist, pair<int, int> curr) {
	if (dist >= k) {
		if (curr == target) ans++;
		return;
	}
	if (visited[target.first][target.second]) return;
	for (int i = 0; i < 4; i++) {
		int nextRow = curr.first + dRow[i];
		int nextCol = curr.second + dCol[i];
		if (nextRow < 0 || nextRow >= r) continue;
		if (nextCol < 0 || nextCol >= c) continue;
		if (board[nextRow][nextCol] == 'T') continue;
		if (visited[nextRow][nextCol]) continue;
		visited[nextRow][nextCol] = true;
		BT(dist + 1, { nextRow,nextCol });
		visited[nextRow][nextCol] = false;
	}
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	
	cin >> r >> c >> k;
	for (int i = 0; i < r; i++) {
		for (int j = 0; j < c; j++) {
			cin >> board[i][j];
		}
	}
	start = { r - 1,0 };
	target = { 0,c - 1 };
	visited[start.first][start.second] = true;
	BT(1, start);
	cout << ans;
};