题解 | #句子逆序#双指针做法

#include <iostream>
#include <string>
using namespace std;
void swapString(string& a, int fast, int low) {
    //将字符串全部翻转
    char temp;
    while (low < fast) {
        temp = a[low];
        a[low] = a[fast];
        a[fast] = temp;
        low++;
        fast--;
    }
}

void prString(string a) {

    int fast = a.size() - 1;
    int low = 0;
    //将字符串全部翻转
    swapString(a, fast, low);
    //按正确顺序输出
    fast = 0;
    low = 0;
    while (fast <= a.size()) {
        if (a[fast] == ' ' || fast == a.size()) {
            swapString(a, fast - 1, low);
            low = fast + 1;
        }
        fast = fast + 1;
    }

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

}

int main() {
    string s;
    getline(cin, s);
    prString(s);

    return 0;
}
// 64 位输出请用 printf("%lld")