Two ways to get numeric value in string
https://discuss.leetcode.com/topic/5172/simple-accepted-java-solution
Character.getNumericValue(char)
public class Solution {
public String addBinary(String a, String b) {
if(a == null || a.isEmpty()) {
return b;
}
if(b == null || b.isEmpty()) {
return a;
}
char[] aArray = a.toCharArray();
char[] bArray = b.toCharArray();
StringBuilder stb = new StringBuilder();
int i = aArray.length - 1;
int j = bArray.length - 1;
int aByte;
int bByte;
int carry = 0;
int result;
while(i > -1 || j > -1 || carry == 1) {
aByte = (i > -1) ? Character.getNumericValue(aArray[i--]) : 0;
bByte = (j > -1) ? Character.getNumericValue(bArray[j--]) : 0;
result = aByte ^ bByte ^ carry;
carry = ((aByte + bByte + carry) >= 2) ? 1 : 0;
stb.append(result);
}
return stb.reverse().toString();
}
}
https://leetcode.com/submissions/detail/95634744/
string.charAt(i) - '0'
public class Solution {
public String addBinary(String a, String b) {
int i = a.length() - 1, j = b.length() - 1;
int carry = 0;
StringBuilder res = new StringBuilder();
while(i >= 0 || j >= 0 || carry != 0){
int sum = carry;
if(i >= 0){
sum += a.charAt(i) - '0';
}
if(j >= 0){
sum += b.charAt(j) - '0';
}
res.append(sum % 2);
carry = sum / 2;
i--;
j--;
}
return res.reverse().toString();
}
}