public static String DecimaltoBinary(int num){

char[] ch = Integer.toBinaryString(num).toCharArray();

String res = "";

if(ch.length == 1 && ch[0] == '0'){

return "0";

}

//从左到右记录幂的位置

int temp = ch.length-1;

String s = "";

for (int i = 0; i < ch.length; i++) {

if (ch[i] == '1') {

if(temp > 2) {

s = DecimaltoBinary(temp);

}else{

s = temp+"";

}

if(res == "") {

res += "2(" + s + ")";

} else {

res += "+" + "2(" + s + ")";

}

}

temp--;

}

return res;

}

就一个递归调用，没有多判断负数，上面有大神已经判断了！不过没想过复杂度的问题，能力不够

创作者周榜