30 lines
457 B
C++
30 lines
457 B
C++
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#include<bits/stdc++.h>
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using namespace std;
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using ll = long long;
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void solve()
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{
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int n;
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cin>>n;
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if(n==1) cout<<"1"<<endl;
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else if(n%2!=0) cout<<"-1"<<endl;
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else
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{
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for(int i=1; i<=n; i+=2)
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{
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cout<<i+1<<" "<<i<<" ";
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}
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cout<<endl;
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}
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}
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int main()
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{
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ios_base::sync_with_stdio(false);
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cin.tie(nullptr);
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int TC = 1;
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cin >> TC;
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cin.ignore();
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while (TC--) solve();
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}
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