QUESTION:
You are given a string s, where every two consecutive vertical bars ‘|’ are grouped into a pair. In other words, the 1st and 2nd ‘|’ make a pair, the 3rd and 4th ‘|’ make a pair, and so forth.
| Return the number of ‘’ in s, excluding the ‘’ between each pair of ‘ | ’. |
| Note that each ‘ | ’ will belong to exactly one pair. |
Example 1:
Input: s = "l|*e*et|c**o|*de|"
Output: 2
Explanation: The considered characters are underlined: "l|*e*et|c**o|*de|".
The characters between the first and second '|' are excluded from the answer.
Also, the characters between the third and fourth '|' are excluded from the answer.
There are 2 asterisks considered. Therefore, we return 2.
Example 2:
Input: s = "iamprogrammer"
Output: 0
Explanation: In this example, there are no asterisks in s. Therefore, we return 0.
Example 3:
Input: s = "yo|uar|e**|b|e***au|tifu|l"
Output: 5
Explanation: The considered characters are underlined: "yo|uar|e**|b|e***au|tifu|l". There are 5 asterisks considered. Therefore, we return 5.
Constraints:
1 <= s.length <= 1000
s consists of lowercase English letters, vertical bars '|', and asterisks '*'.
s contains an even number of vertical bars '|'.
EXPLANATION:
一个for循环,加上一个flag作为前后的标记即可.
SOLUTION:
class Solution {
func countAsterisks(_ s: String) -> Int {
var result:Int = 0
var flag:Bool = true
for ch in s {
if flag {
if ch == "*" {
result += 1
}
}
if ch == "|" {
flag = !flag
}
}
return result
}
}