原题传送门
思路：
输出三种结果： 摸左边墙走，摸右边墙走，最短路线
注意点：
方向是按自己当前方向来算的，第一个路线的方向循环是左上右下，第二个路线的循环是右上左下。
以左路线为例：
思考得之，进入方格的方向是上一格前进时朝向的方向，而当前应该前进的方向是循环内的上一方向。即：如果此时进入方向N，然后应该先向W前进。
DFS运算前两个，BFS运算最短路径
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>using namespace std;
/***************************************/
#define ll long long
#define int64 __int64
/***************************************/
const int INF = 0x7f7f7f7f;
int w, h;
int leftMoveY[4] = {-1, 0, 1, 0};
int leftMoveX[4] = {0, -1, 0, 1}; //左上右下
int rightMoveY[4] = {1, 0, -1, 0};
int rightMoveX[4] = {0, -1, 0, 1}; //右上左下
char chess[50][50];
int vis[50][50];
int leftStep, rightStep, shortStep;
int leftStepTemp, rightStepTemp;
int shortStepTemp[50][50];void leftDFS(int x, int y, int d)
{if (chess[x][y] == 'E'){leftStep = leftStepTemp;return;}int x1, y1;if (d == 0)d = 3;elsed--;for (int i = d; i < 4; i++){x1 = x + leftMoveX[i];y1 = y + leftMoveY[i];if (x1 > 0 && x1 <= h && y1 > 0 && y1 <= w && chess[x1][y1] != '#'){leftStepTemp++;leftDFS(x1, y1, i);}if (leftStep)return;if (i == 3)i = -1;}
}
void rightDFS(int x, int y, int d)
{if (chess[x][y] == 'E'){rightStep = rightStepTemp;return;}int x1, y1;if (d == 0)d = 3;elsed--;for (int i = d; i < 4; i++){x1 = x + rightMoveX[i];y1 = y + rightMoveY[i];if (x1 > 0 && x1 <= h && y1 > 0 && y1 <= w && chess[x1][y1] != '#'){rightStepTemp++;rightDFS(x1, y1, i);}if (rightStep)return;if (i == 3)i = -1;}
}void BFS(int x, int y)
{queue<int> Q;Q.push(x);Q.push(y);int x1, y1;while (!Q.empty()){x1 = Q.front();Q.pop();y1 = Q.front();Q.pop();if (vis[x1][y1] == 1)continue;vis[x1][y1] = 1;for (int i = 0; i < 4; i++){int x2 = x1 + leftMoveX[i];int y2 = y1 + leftMoveY[i];if (!vis[x2][y2] && ((chess[x2][y2] == '.') || (chess[x2][y2] == 'E'))){Q.push(x2);Q.push(y2);shortStepTemp[x2][y2] = shortStepTemp[x1][y1] + 1;if (chess[x2][y2] == 'E'){shortStep = shortStepTemp[x2][y2];return;}}}}
}int main()
{int n;cin >> n;while (n--){memset(chess, 0, sizeof(chess));memset(vis, 0, sizeof(vis));memset(shortStepTemp, 0, sizeof(shortStepTemp));leftStep = rightStep = shortStep = leftStepTemp = rightStepTemp = 0;cin >> w >> h;int sx, sy;for (int i = 1; i <= h; i++)for (int j = 1; j <= w; j++){cin >> chess[i][j];if (chess[i][j] == 'S')sx = i, sy = j;}leftDFS(sx, sy, 1);rightDFS(sx, sy, 1);BFS(sx, sy);cout << leftStep + 1 << ' ' << rightStep + 1 << ' ' << shortStep + 1<< endl;}system("pause");return 0;
}