//数组中元素交换 #include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int i,a[10000],n,b,j; cin>>n; for(i=0;i<n;i++){ cin>>a[i]; } for(i=0;i<n-1;i+=2){ b=a[i]; a[i]=a[i+1]; a[i+1]=b; } for(i=0;i<n;i++){ cout<<a[i]<<" "; } return 0; }