可直接复制

可直接复制
#include<bits/stdc++.h>
using namespace std;

int main (){
long long a[200010];
long long b=0,c=0,n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
}
for(int i=1;i<=n;i+=2){
c=a[i+1];
b=a[i];
a[i]=c;
a[i+1]=b;
cout<<a[i]<<" "<<a[i+1]<<" ";
}
}