题目:67. 二进制求和
思路:
模拟加法即可。
代码:
class Solution {
public String addBinary(String a, String b) {
int carry = 0;
StringBuilder res = new StringBuilder();
for (int i = a.length() - 1, j = b.length() - 1; i >= 0 || j >= 0; i --, j--) {
int anum = i >= 0? a.charAt(i) - '0': 0;
int bnum = j >= 0? b.charAt(j) - '0': 0;
carry = carry + anum + bnum;
res.append(carry % 2);
carry /= 2;
}
if (carry > 0) {
res.append(carry);
}
return res.reverse().toString();
}
}
class Solution {
public String addBinary(String a, String b) {
int alen = a.length() - 1;
int blen = b.length() - 1;
int carry = 0;
StringBuilder res = new StringBuilder();
while (alen >= 0 && blen >= 0) {
int anum = a.charAt(alen) - '0';
int bnum = b.charAt(blen) - '0';
res.append((anum + bnum + carry) % 2);
carry = (anum + bnum + carry) / 2;
alen --;
blen --;
}
while (alen >= 0) {
int anum = a.charAt(alen) - '0';
res.append((anum + carry) % 2);
carry = (anum + carry) / 2;
alen --;
}
System.out.println();
while (blen >= 0) {
int bnum = b.charAt(blen) - '0';
res.append((bnum + carry) % 2);
carry = (bnum + carry) / 2;
blen --;
}
if (carry > 0) {
res.append(carry);
}
return res.reverse().toString();
}
}