題目描述

將一個正整數(shù)分解質因數(shù)。例如：輸入90,打印出90 = 2 * 3 * 3 * 5。

    public static String acquirePrime(int num){
        StringBuilder sb = new StringBuilder();

        int cursor =2;

        while (cursor<=num){
            if (cursor==num){
                sb.append(num);
                break;
            }else if (num % cursor == 0){
                sb.append(cursor).append("*");
                num = num / cursor;
            }else {
                cursor++;
            }
        }
        return sb.toString();
    }