This is solution to Sagheer The Hausmeister (812B) problem in Codeforces

SagheerTheHausmeister.java

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class SagheerTheHausmeister {

	private static BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
	private static int M_MAX;
	private static int N,M;
	private static int MATRIX [][] = new int [16][150];
	private static int ILL [] = new int [16]; // has index of last bulb while entering from left.
	private static int ILR [] = new int [16]; // has index of last bulb while entering from right.
	private static int FINAL_FLOOR_WHERE_BULB_IS_PRESENT =0;

	private static void readInput(){
		try {
			String[] NM = buf.readLine().split("\\s"); 
			N = Integer.parseInt(NM[0]); // total floors in building.
			M = Integer.parseInt(NM[1]); // cols in building.
			M_MAX = M+2;// M_MAX is the total cols of building including stairs on either sides.
			for (int i=0;i<N;i++) {
				String AR[] = buf.readLine().split("");
				for (int j=0;j<M_MAX;j++) {					
					MATRIX[i][j] = Integer.parseInt(AR[j]);
					if (MATRIX[i][j]==1) {
						ILL[N-i-1] = j;
						ILR[N-i-1] = Math.max(M_MAX-j-1,ILR[N-i-1]);
						FINAL_FLOOR_WHERE_BULB_IS_PRESENT = Math.max(FINAL_FLOOR_WHERE_BULB_IS_PRESENT,N-i-1);;
					}					 
				}			 
			}
		} catch (Exception e) {
			System.out.println("Excepiton while input "+e);
		} 		
	}

	private static int minTime(boolean isLeft, int floor, int totalDist) {
		// base case
		if (floor == FINAL_FLOOR_WHERE_BULB_IS_PRESENT) {
			if (isLeft) {
				totalDist += ILL[floor];				 
			} else {
				totalDist += ILR[floor]; 
			}
			return totalDist;
		} else {

			// totalDistToLeft is moving from current position to next floor from left most stairs
			// totalDistToRight is moving from current position to next floor from right most stairs
			// return min distance after going to next floor through left and right
			if (isLeft) {
				totalDist += ILL[floor];
				int totalDistToLeft = totalDist + ILL[floor] + 1;				
				int totalDistToRight = totalDist + (M_MAX-ILL[floor]-1) +1;
				return Math.min( 
						minTime(true, floor+1, totalDistToLeft),
						minTime(false, floor+1, totalDistToRight)); 

			} else {				
				totalDist += ILR[floor];
				int totalDistToLeft = totalDist + (M_MAX-ILR[floor]-1) +1;
				int totalDistToRight = totalDist + ILR[floor] +1;
				return Math.min(
						minTime(true, floor+1, totalDistToLeft),
						minTime(false, floor+1, totalDistToRight));
			}
		}
	}

	public static void main(String abc[]){
		readInput();
		int result = minTime(true,0,0);
		System.out.println(result);
	}
}