BFS

#include<iostream>; using namespace std; int queuex[]; int queuey[]; int visit[][]; int dx[]={-1,0,0,1}; int dy[]={0,1,-1,0}; int rear; int BFS(int startx, int starty) { int front = rear = 0; queuex[rear]=startx; queuey[rear]=starty; rear++; visit[startx][starty]=1; while(front !=rear) { int x = queuex[front]; int y = queuey[front]; front++; for(int move = 0; move <4; move++) { int xNext = x + dx[move]; int yNext = y + dy[move]; if(visit[xNext][yNext]==0) { queuex[rear]=xNext; queuey[rear]=yNext; rear++; visit[xNext][yNext] = 1; } } } return -1; }