单词首字母大写，删除多余空格

输入：
“ this is my csdn blog ”
输出：
"This Is My Csdn Blog"

int main(){    string str;    while (getline(cin, str))    {        int i = 0;        while (str[i] == ' ')        {            i++;        }        int j = str.length() - 1;        while (str[j] == ' ')        {            j--;        }        str = str.substr(i, j - i + 1);        string res = "";        res += str[0] - 32;        for (int i = 1; i < str.length(); i++)        {            if (str[i] != ' ')            {                if (str[i - 1] == ' ')                {                    res += ' ';                    str[i] -= 32;                }                res += str[i];            }        }        cout<<res<<endl;    }    return 0;}