LeetCode 434. Number of Segments in a String

题目描述：

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

比较简单，注意处理连续的空格和结尾。还有有符号数与无符号数的隐式转换问题。

class Solution {
public:
    int countSegments(string s) {
        int prevIndex = -1, ans = 0;
        for(int i = 0; i < s.length(); i++){
            if(s[i] == ' '){
                if(prevIndex != i - 1){
                    ans++;
                }
                prevIndex = i;
            }
        }
        if(prevIndex < (int)s.length() - 1) ans++;
        return ans;
    }
};