题解 | #单词倒排#

#include <iostream>
#include <string>

using namespace std;

//将不是字符的内容使用空格替换
void changeOther(string& s) {
    for (int i = 0; i < s.size(); i++) {
       if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z') )
            continue;
        else 
            s[i] = ' ';
    }

}

void mySwap(string& s, int start, int end) {
    for (; start < end; start++, end--) {
        swap(s[start], s[end]);
    }
}

int main() {

    string s;
    getline(cin, s);
    //先将不是字符的内容使用空格替换
    changeOther(s);

    //将字符到过来
    mySwap(s, 0, s.size() - 1);
    
    int fast = 0;
    int low = 0;
    
    while ( fast+1 <= s.size()) {
        if (s[fast + 1 ]  == ' ' || fast == s.size()-1) {
            if ((s[fast] >= 'a' && s[fast] <= 'z') || (s[fast] >= 'A' && s[fast] <= 'Z') ) {
                mySwap(s, low, fast);
                low = fast + 2;
            }
        }
        fast++;

    }
    for (int i = 0; i < s.size(); i++) {
        cout << s[i];
    }

    return 0;
    

}