1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
| class Solution {
public String addStrings(String num1, String num2) {
Map<Character, Integer> map = new HashMap<>(10);
char num = '0';
for (int i = 0; i < 10; i++) {
map.put(num, i);
num++;
}
StringBuilder ans = new StringBuilder();
int p1 = num1.length() - 1, p2 = num2.length() - 1;
int carry = 0;
while (p1 >= 0 || p2 >= 0) {
int tmp;
if (p1 >= 0 && p2 >= 0) {
tmp = map.get(num1.charAt(p1)) + map.get(num2.charAt(p2));
} else if (p1 < 0) {
tmp = map.get(num2.charAt(p2));
}else{
tmp = map.get(num1.charAt(p1));
}
if (carry != 0) {
tmp += 1;
carry = 0;
}
if (tmp >= 10) {
tmp -= 10;
carry = 1;
}
ans.append(tmp);
p1--;
p2--;
}
if (carry != 0) {
ans.append(carry);
}
return ans.reverse().toString();
}
}
|
