整理一下网上关于这道题和自己关于这道题的解法
方法一: 利用a+b和b+a进行比较选择其中数值较大的组合方式
public class Solution {public void maxValueNum(int[] array) {int len = array.length;String maxValueStr = "";for(int i=0;i<len;i++) {for(int j=0;j<len-1-i;j++) {String str = "";if((array[j]+str+array[j+1]).compareTo(array[j+1]+str+array[j]) > 0) {swap(array, j, (j+1));}}maxValueStr += array[len-1-i];}System.out.println(maxValueStr);}public void swap(int[] array, int a, int b) {int tmp = array[a];array[a] = array[b];array[b] = tmp;}
}main函数:
public class Main {public static void main(String[] args) {Solution s = new Solution();int[] array = {195,23,56,235,7};s.maxValueNum(array);}
}运行结果为: 75623523195方法二: 利用compare函数特性来进行排序选择
public class Solution1 {public void maxValueNum(int[] array) {int len = array.length;String maxValueStr = "";for(int i=0;i<len;i++) {for(int j=0;j<len-1-i;j++) {if(compare(array[j], array[j+1]) > 0) {swap(array, j, (j+1));}}maxValueStr += array[len-1-i];}System.out.println(maxValueStr);}public int compare(int a, int b) {int count1 = 0;int count2 = 0;int middleNum1 = a;int middleNum2 = b;while(middleNum1 != 0) {count1++;middleNum1 /= 10;}while(middleNum2 != 0) {count2++;middleNum2 /= 10;}int num1 = (int) (a*Math.pow(10,count2)+b);int num2 = (int) (b*Math.pow(10,count1)+a);return num1 > num2 ? 1 : (num1 == num2 ? 0 : -1);}public void swap(int[] array, int a, int b) {int tmp = array[a];array[a] = array[b];array[b] = tmp;}
}main函数:
public class Main {public static void main(String[] args) {Solution1 s1 = new Solution1();int[] array = {195,23,56,235,7};s1.maxValueNum(array);}
}运行结果为: 75623523195方法三: 利用贪心算法每次求最优值
public class Solution2 {public void maxValueNum(int[] array) {int len = array.length;String maxValueStr = "";for(int i=0;i<len;i++) {for(int j=0;j<len-1-i;j++) {String str = "";if((array[j]+str).compareTo(array[j+1]+str) > 0) {swap(array, j, (j+1));}}maxValueStr += array[len-1-i];}System.out.println(maxValueStr);}public void swap(int[] array, int a, int b) {int tmp = array[a];array[a] = array[b];array[b] = tmp;}
}main函数:
public class Main {public static void main(String[] args) {Solution2 s2 = new Solution2();int[] array = {195,23,56,235,7};s2.maxValueNum(array);}
}运行结果为: 75623523195