SetToZero.java

//http://coolcodebro.blogspot.com/2012/12/book-cracking-coding-interview-question.html

public class SetToZero {
	public static void main(String[] args) {
		new SetToZero().run();
	}
	
	void run() {
		int[][] matrix = { {1, 2, 3, 9, 5}, {1, 1, 0, 5, 2}};
		printMatrix(matrix);

		setToZero(matrix);
		
		System.out.println();
		printMatrix(matrix);
	}

	void setToZero(int[][] matrix) {
		boolean[] rows = new boolean[matrix.length];
		boolean[] cols = new boolean[matrix[0].length];

		for(int i=0; i<rows.length; i++) {
			for(int j=0; j<cols.length; j++) {
				if(matrix[i][j] == 0) {
					rows[i] = true;
					cols[j] = true;
				}
			}
		}
		
		//Set rows to 0
		for(int i=0; i<rows.length; i++) {
			if(rows[i]) {
				for(int j=0; j<cols.length; j++)
					matrix[i][j] = 0;
			}
		}
		
		//Set columns to 0
		for(int i=0; i<cols.length; i++) {
			if(cols[i]) {
				for(int j=0; j<rows.length; j++)
					matrix[j][i] = 0; 
			}
		}
	}

	void printMatrix(int[][] matrix) {
		for(int i=0; i<matrix.length; i++) {
			for(int j=0; j<matrix[i].length; j++)
				System.out.print(matrix[i][j] + " ");
			System.out.println();			
		}
	}
}