Java -- 给定一个int数组，拼接出最大数值

Posted 2021-02-16 学习是不让自己瞎想的最好方式

public class ZhiJieTiaoDong {

    /*
        给定一个数组：组合成最大数值
     */
    public String szpj(int[] args){
        if(null == args || args.length == 0){
            return "";
        }
        StringBuilder stringBuilder = new StringBuilder();
        int[] yxsz = compareSZ(args);
        for (int i = args.length - 1; i >= 0; i--){
            stringBuilder.append(String.valueOf(args[i]));
        }
        return stringBuilder.toString();
    }

    /*
        排序
     */
    private int[] compareSZ(int[] args){
        if(null == args){
            throw new NullPointerException();
        }
        if (args.length == 1){
            return args;
        }
        int change = 0;
        for(int i = 0; i < args.length - 1; i++){
            for(int j = i + 1; j < args.length; j++){
                if(compare(args[i], args[j])){
                    change = args[i];
                    args[i] = args[j];
                    args[j] = change;
                }
            }
        }
        return args;
    }

    /*
        比较两个数字哪个作高位排列
        example: 9, 98 --> 998; 15, 18 --> 1815
     */
    private boolean compare(int a, int b){
        String aa = String.valueOf(a);
        String bb = String.valueOf(b);
        int ab = Integer.valueOf(aa + bb);
        int ba = Integer.valueOf(bb + aa);
        if(ab >= ba){
            return true;
        }else {
            return false;
        }
    }

    public static void main(String[] args){
        ZhiJieTiaoDong zhiJieTiaoDong = new ZhiJieTiaoDong();
        int[] a = {10,21,13,24};
        int[] b = {35,11,23,4,34};
        int[] c = {0, 4,2, 32, 11, 22, 11};
        System.out.println(zhiJieTiaoDong.szpj(c));
    }



}