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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. #define int long long
  4. #define pb push_back
  5. #define all(a) (a).begin(),(a).end()
  6. #define sz(x) (int)x.size()
  7. #define endl "\n"
  8. #define inf 1000000007
  9. #define FOR(i, a, b) for(int i=a; i<b; i++)
  10. int dp[110] = {0};
  11.  
  12. void solve(){
  13. 	int n, m, cost=0, rem;
  14. 	cin>>n>>m;
  15. 	vector<int> adj[n];
  16. 	int arr[n];
  17. 	FOR(i, 0, n) cin>>arr[i];
  18. 	sort(arr, arr+n);
  19. 	if(m<n || n==2){
  20. 		cout<<"-1"<<endl;
  21. 		return;
  22. 	}
  23. 	FOR(i, 1, n){
  24. 		cost+=(arr[i]+arr[i-1]);
  25. 	}
  26. 	cost+=(arr[0]+arr[n-1]);
  27. 	rem=m-(n);
  28. 	cost+=rem*(arr[0]+arr[1]);
  29. 	cout << cost << endl;
  30. 	int a=1;
  31. 	for(int i=0;i<n-1;i++){
  32. 		cout <<a <<" "<< a+1<< endl;
  33. 		a++;
  34. 	}
  35. 	cout <<"1" <<" "<< n << endl;
  36. 	for(int i=0;i<(m-n);i++){
  37. 		cout <<"1" <<" "<<"2" << endl;
  38. 	}
  39. }
  40. signed main(){
  41. 	#ifdef _DEBUG
  42. 		freopen("input.txt", "r", stdin);
  43.     	freopen("output.txt", "w", stdout);
  44. 	#endif
  45.  
  46. 	ios::sync_with_stdio(false);
  47. 	cin.tie(0);
  48. 	int t=1;
  49. 	cin>>t;
  50. 	while(t--){
  51. 		solve();
  52. 	}
  53. 	return 0;
  54.  
  55. }
Success #stdin #stdout 0s 4412KB
comments (?)
stdin
copy 
4
4 6
1 1 1 1
3 1
1 2 3
3 4
1 2 3
4 6
1 2 3 4
stdout
copy 
12
1 2
2 3
3 4
1 4
1 2
1 2
-1
15
1 2
2 3
1 3
1 2
26
1 2
2 3
3 4
1 4
1 2
1 2
https://ideone.com/sOY4oW
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
public

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