DFS-深度优先算法解决迷宫问题

/*
main.cpp
*/
#define  _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;

int sr, sc, dr, dc;
int R,C,minLen = 100;
char grid[10][10];
bool found[10][10];

void dfs(int r, int c, int len);

int main()
{
    freopen("./data.in", "r", stdin);
    cin >> R >> C;
    for (int i = 0; i < R;i++)
    for (int j = 0; j < C; j++)
    {
        cin >> grid[i][j];
        if (grid[i][j] == 'S'){ sr = i; sc = j; }
        if (grid[i][j] == 'D'){ dr = i; dc = j; }
        found[i][j] = false;
    }
    dfs(sr, sc, 0);
    cout << minLen << endl;
    return 0;
}
int d[4][2] = { { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };

void dfs(int r, int c, int len)
{
    if (r == dr&&c == dc)
    {
        if (minLen > len)
            minLen = len;
        return;
    }
    for (int i = 0; i < 4; i++)
    {
        int nextR = r + d[i][0];
        int nextC = c + d[i][1];
        if (nextR < 0 || nextR >= R || nextC < 0 || nextC >= C) continue;
        if (grid[nextR][nextC] == 'X') continue;
        if (found[nextR][nextC] == true) continue;
        found[nextR][nextC] = true;
        dfs(nextR, nextC, len + 1);
        found[nextR][nextC] = false;
    }
}

6 6
S.XD..
..XXX.
...X..
......

data.in文件