题解 | #首字母大写#

#include <iostream>
using namespace std;

int main() {
    string str;
    getline(cin, str);
    int flag =
        0; //flag=0，表示当前遇到了空格或其他字符，若下一次遇到字母，直接变成大写就可以
    for (int i = 0; i < str.length(); i++) {
        if ('a' <= str[i] && str[i] <= 'z') { //是小写字母
            if (flag == 0) {
                if(('0'<=str[i-1]&&str[i-1]<='9'||'a' <= str[i-1] && str[i-1] <= 'z')&&i>0)
                    continue;
                str[i] = str[i] - 32; //a是97，A是65，小写转大写减32
                flag = 1;
            }
        }
        if (str[i] == ' ' || str[i] == '\t' || str[i] == '\r' || str[i] == '\n' ||
                str[i] == ',' || str[i] == '.') {
            flag = 0;
        }
    }
    cout << str;
}
// 64 位输出请用 printf("%lld")