| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 501016 | dostigator | Gift (IZhO18_nicegift) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
// author lox:(
#pragma GCC optimize("O3")
#pragma GCC target("popcnt")
#include <bits/stdc++.h>
using namespace std;
#define popcnt __builtin_popcount
#define all(a) a.begin(),a.end()
#define low_b lower_bound
#define up_b upper_bound
#define vii vector<pair<ll,ll>>
#define vll vector<pair<ll,ll>>
#define pii pair<ll,ll>
#define mii map<ll,ll>
#define pll pair<ll,ll>
#define mll map<ll,ll>
#define vi vector<ll>
#define vl vector<ll>
#define pb push_back
#define endl '\n'
#define Y second
#define X first
typedef long double ld;
typedef long long ll;
const ll dx[4]={1,-1,0,0},dy[4]={0,0,1,-1},col=107,N=3e6+777;
const ll mod=1e9+7,inf=1e18;
void fre_open(){freopen("file.in","r",stdin);freopen("file.out","w",stdout);}
ll binpow(ll n,ll k){if(k<0)return 0ll;if(k==0)return 1ll;if(k%2)return (binpow(n,k-1)*n)%mod;ll kk=binpow(n,k/2)%mod;return (kk*kk)%mod;}
void solve(){
int n;
cin>>n;
pii a[n+2];
for(int i=1; i<=n; ++i){
cin>>a[i].X;
a[i].Y=i;
sum+=a[i];
}
sort(a+1,a+1+n);
if(sum%k) {cout<<"-1\n";return;}
cout<<sum/2<<endl;
for(int i=1; i<=sum/2; ++i){
cout<<"1 "<<a[n].y<<' '<<a[n-1].y<<endl;
a[n].x--;
a[n-1].x--;
sort(a+1,a+1+n);
}
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//fre_open
ll tt=1;
//cin>>tt;
while(tt--) solve();
}