package leetcode
import (
"strconv"
"strings"
)
func addBinary(a string, b string) string {
if len(b) > len(a) {
a, b = b, a
}
res := make([]string, len(a)+1)
i, j, k, c := len(a)-1, len(b)-1, len(a), 0
for i >= 0 && j >= 0 {
ai, _ := strconv.Atoi(string(a[i]))
bj, _ := strconv.Atoi(string(b[j]))
res[k] = strconv.Itoa((ai + bj + c) % 2)
c = (ai + bj + c) / 2
i--
j--
k--
}
for i >= 0 {
ai, _ := strconv.Atoi(string(a[i]))
res[k] = strconv.Itoa((ai + c) % 2)
c = (ai + c) / 2
i--
k--
}
if c > 0 {
res[k] = strconv.Itoa(c)
}
return strings.Join(res, "")
}