//http://xiaoyaoworm.com/blog/2015/04/08/%E6%96%B0leetcode-sort-5-largest-number/ public class Solution { public String largestNumber(int[] num) { String[] numStr = new String[num.length]; for(int i = 0; i < num.length; i++){ numStr[i] = String.valueOf(num[i]); } Comparator comparator = new Comparator(){ public int compare(String x, String y){ String leftRight = x.concat(y); String rightLeft = y.concat(x); return rightLeft.compareTo(leftRight); } }; Arrays.sort(numStr, comparator); StringBuffer sb = new StringBuffer(); for(String n: numStr){ sb.append(n); } java.math.BigInteger result = new java.math.BigInteger(sb.toString()); return result.toString(); } }