public void merge(int[] A, int m, int[] B, int n) {
		int countA = m - 1;
		int countB = n - 1;
		for(int i = n + m - 1; i >= 0; --i){
			if(countA >= 0 && countB >= 0 && A[countA] > B[countB]){
				A[i] = A[countA];
				countA--;
				continue;
			}
			if(countA >= 0 && countB >= 0 && A[countA] <= B[countB]){
				A[i] = B[countB];
				countB--;
				continue;
			}
		}
		//still have B
		while(countB >= 0){
			A[countB] = B[countB];
			countB--;
		}
	}