题解-4

#include <bits/stdc++.h>
using namespace std;
int a[1000005];
int main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for (int i = 0; i < n; i += 2) {
        swap(a[i],a[i + 1]);
    }


    for (int i = 0; i < n; i++) {
       	cout <<a[i];
        if (i < n - 1) {
            cout << " ";
        }
    }
    cout << endl;

    return 0;
}

直接放代码