Given a array consisted of only 0 or 1, and a number N. We have N times to flip 0 to 1 in array. Find the longest continuous 1 after we flipped the N zero elements. Rotation is NOT allowed. For example, 100100111000, n=2, the best flip is 100111111000, return 6 10001101101, n=2, the best flip is 10001111111, return 7

findContinuous1sRec

public static int findContinuous1s(String s, int maxFlips){
		int[] max = new int[1];
		findContinuous1sRec(s, 0, 0, maxFlips, 0, max);
		return max[0];
	}
	
	public static void findContinuous1sRec(String s, int start, int current, int maxFlips, int flips, int[] max){		
		//keep on eating up 1s if we can
		while(current<s.length() && s.charAt(current) == '1')
			current++;
		
		if(current == s.length()){
			max[0] = Math.max(max[0], current-start);
			return;
		}
		
		//current char is 0 
		//we can flip and we decide to flip
		if(flips<maxFlips)
			findContinuous1sRec(s, start, current+1, maxFlips, flips+1, max);
		
		//if we can't flip or we decide to not flip
		max[0] = Math.max(max[0], current-start);
		//set start = current+1 and continue search
		findContinuous1sRec(s, current+1, current+1, maxFlips, flips, max);

	}