forked from DengWangBao/Leetcode-Java
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathNumberOfDigitOne.java
More file actions
32 lines (27 loc) · 814 Bytes
/
NumberOfDigitOne.java
File metadata and controls
32 lines (27 loc) · 814 Bytes
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
public class NumberOfDigitOne {
/**
* 下面要注意所有局部变量都是long的，因为factor*10可能会溢出
*/
public int countDigitOne(int n) {
long count = 0, factor = 1;
long low = 0, cur = 0, high = 0;
while (n / factor > 0) {
low = n % factor;
cur = (n / factor) % 10;
high = n / (factor * 10);
switch ((int) cur) {
case 0:
count += high * factor;
break;
case 1:
count += high * factor + low + 1;
break;
default:
count += (high + 1) * factor;
break;
}
factor *= 10;
}
return (int) count;
}
}