题解 | #句子逆序#

#include <iostream>
#include <string>
using namespace std;
//反转字符串
void reverse(string & s, int l, int r) {
    while(l < r) {
        swap(s[l], s[r]);
        l++;
        r--;
    }
}

int main() {
    string s;
    getline(cin, s);
    reverse(s, 0, s.size()-1);
    int start = 0;
  
    for(int i = 0; i < s.size(); i++) {
        if(s[i] == ' '){
            reverse(s, start, i-1);
            start = i+1;
        }
    }
  //反转最后一个
    reverse(s, start, s.size()-1);
    cout << s;
    return 0;
}