Largest Number
Given a list of non negative integers, arrange them such that they form the largest number.
For example, given [3, 30, 34, 5, 9]
, the largest formed number is 9534330
.
Note: The result may be very large, so you need to return a string instead of an integer.
其实问题可以转化为数组排序,排序的依据是例如3和30,330大于303于是3应该排在30的前面,至于如何比较可以直接使用String的compareTo()方法。其中需要注意的细节是数组全为0的情况。代码如下:
public class Solution { //判断a,b的位置,a在b之前返回true否则返回false public boolean compare(int a,int b) { String s1 = String.valueOf(a); String s2 = String.valueOf(b); String sum1 = s1+s2; String sum2 = s2+s1; if(sum1.compareTo(sum2)>=0) return true; else return false; } public String largestNumber(int[] num) { String re = ""; int size = num.length; //冒泡排序,每次将最小的沉底 for(int i=0;i<size-1;i++) { for(int j=0;j<size-i-1;j++) { if(!compare(num[j],num[j+1])) { int tmp = num[j]; num[j] = num[j+1]; num[j+1] = tmp; } } } int sum = 0; for(int k=0;k<size;k++) { sum+=num[k]; re = re+num[k]; } if(sum==0){ re = "0"; } return re; } }