DFS-深度优先遍历

#include <iostream>
 
/*
5 4
0 0 1 0
0 0 0 0
0 0 1 0
0 1 0 0
0 0 0 1
0 0 4 1
 
Total: 9 7 5
Min: 5
--------------------------------
Process exited with return value 0
Press any key to continue . . .
*/
 
using namespace std;
 
int n, m;
int minnum = 9999999;
int endy1 = 0, endy2 = 0;
int maze[20][20] = {0}, book[20][20] = {0};
int direction[4][2] = { {0, 1}, {1, 0}, {0, -1}, {-1, 0} };
 
void DFS(int x, int y, int step)
{
	if(x == endy1 && y == endy2)
	{
		if(step < minnum)
		{
			minnum = step;
			cout << minnum << " ";
		}
 
		return;
	}
 
	 for(int i = 0; i <= 3; i++)
	 {
	 	int tx = x + direction[i][0];
	 	int ty = y + direction[i][1];
 
	 	if(tx < 0 || tx > n - 1 || ty < 0 || ty > m - 1)
	 	{
	 		continue;
	 	}
 
	 	if(maze[tx][ty] == 0 && book[tx][ty] == 0)
	 	{
	 		book[tx][ty] = 1;
	 		DFS(tx, ty, step + 1);
	 		book[tx][ty] = 0;//尝试结束，取消这个点的标记
	 	}
	 }
 
	 return;
}
 
int main()
{
	cin >> n >> m;
 
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < m; j++)
		{
			cin >> maze[i][j];
		}
	}
 
	int beginx1, beginx2;
	cin >> beginx1 >> beginx2 >> endy1 >> endy2;
 
	cout << endl << "Total: ";
	DFS(beginx1, beginx2, 0);
 
	cout << endl << "Min: " << minnum;
 
	return 0;
}