GoogleJam_Cross the maze

#include<fstream>#include<iostream>using namespace std;#define maxn 102#define limit 10000char matrix[maxn][maxn];char path[maxn*maxn];//[i,j+1] [i-1,j]  [i,j-1]  [i+1,j]//0 's',   1 'e',   2'n',    3'w'  int left_pos[4][2] = {{0,1},{-1,0},{0,-1},{1,0}};int next_pos[4][2] = {{1,0},{0,1},{-1,0},{0,-1}};char direction[4] = {'S','E','N','W'};int turnLeft(int cur){return (cur+1+4)%4;}int turnRight(int cur){return (cur-1+4)%4;}int func(int sx,int sy,int ex,int ey){int ret = 0;int old_ret = ret;int i = sx;int j = sy;int cur_dir = -1;int complete = 0;int k = 0;int start_dir;while(k <4 ){if(matrix[i+left_pos[k][0]][j+left_pos[k][1]] == '#' && matrix[i+next_pos[k][0]][j+next_pos[k][1]] == '.'){cur_dir = k;break;}k++;}if(cur_dir < 0) return -1;start_dir = cur_dir;while(ret < limit){if(matrix[i+next_pos[cur_dir][0]][j+next_pos[cur_dir][1]] == '.'){i += next_pos[cur_dir][0];j += next_pos[cur_dir][1];path[ret++] = direction[cur_dir];if(i == ex && j == ey) return ret;k = 0;}if(k >= 3) break; if(ret > 0 && i == sx && j== sy ) break;if(matrix[i+left_pos[cur_dir][0]][j+left_pos[cur_dir][1]] == '.')cur_dir = turnLeft(cur_dir);else if(matrix[i+next_pos[cur_dir][0]][j+next_pos[cur_dir][1]] == '#')cur_dir = turnRight(cur_dir);k++;}return -1;}int main(){int T,N,sx,sy,ex,ey;ifstream in("D-large-practice.in");ofstream out("d.out");in>>T;for(int i = 0;i<T;i++){in >> N;for(int j = 1;j<=N;j++){for(int k = 1;k<=N;k++){in>>matrix[j][k];}}for(int j = 0;j<=N+1;j++){matrix[0][j] = '#';matrix[N+1][j] = '#';matrix[j][0] = '#';matrix[j][N+1] = '#';}in>>sx>>sy>>ex>>ey;int ret = func(sx,sy,ex,ey);out<<"Case #"<<i+1<<": ";if(ret < 0){out<<"Edison ran out of energy."<<endl;}else{out<<ret<<endl;for(int k = 0;k< ret;k++)out<<path[k];out<<endl;}}in.close();out.close();return 0;}