LeetCode-Easy部分中标签为String 434. Number of Segments in a String
2017-04-08 09:27:14         来源：极致

LeetCode-Easy部分中标签为String 434. Number of Segments in a String。

### 原题

Count the number of segments in a string, where a segment is defined to be a contiguous sequence of non-space characters.

Please note that the string does not contain any non-printable characters.

Example:

```Input: "Hello, my name is John"
Output: 5```
```Input: "          "
Output: 0```
```Input: "     a"
Output: 1```
```Input: "     a        "
Output: 1```
```Input: "     a                b    "
Output: 2```

### 代码分析

a segment is defined to be a contiguous sequence of non-space characters.

```        //字符串的第一个片段的首字符，找到有效字符开始
private bool isValidBegin(char curchar)
{
if (curchar != ' ')
return true;
return false;
}

//判断字符片段的结束
private bool isValidEnd(char curchar, char afterchar)
{
if (curchar != ' ' && afterchar == ' ')
return true;
return false;
}```

### 代码实现

```       public int CountSegments(string s)
{
if (string.IsNullOrEmpty(s))
return 0;
int i = 0;
while (i < s.Length && !isValidBegin(s[i]))
i++;
if (i == s.Length) //没有有效字符，如"         "
return 0;
if (i == s.Length - 1)  //只有一个有效字符，如 "         a"
return 1;
while (i < s.Length - 1 && !isValidEnd(s[i], s[i + 1]))
i++;
if (i == s.Length - 1)
return 1; //只有1个有效字符，如"         a              "

return 1+ CountSegments(s.Substring(i + 1));
}```