Link to this code:
https://cses.fi/paste/553f31d7b208b0942e7ac3//// BISMILLAHIR RAHMANIR RAHEEM
/// ALLAH IS WATCHING ME
/// Every soul shall taste death.
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
/// order_of_key return number of elements less than x.
/// find_by_order return index.
using namespace std;
using namespace __gnu_pbds;
#define MUHAMMAD ios::sync_with_stdio(0);cin.tie(0);
#define all(x) (x).begin(), (x).end()
#define AE cout << fixed << setprecision(10);
#define ld double
#define f first
#define ss second
/// faster.
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma warning(disable:4786)
#pragma warning(disable:4996)
int dx8[] = {0, 0, 1, 1, 1, -1, -1, -1}; // 8-direction.......
int dy8[] = {1,-1, 1, -1, 0, 0, -1, 1};
int dx4[]= {1,-1,0,0}; // 4-direction...........
int dy4[]= {0,0,1,-1};
using ll = long long;
const ll MOD =(1LL<<63);
/// const ld PI = acos(-1.0);
typedef tree< int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<pair<int, int>,null_type,less<pair<int, int>>,rb_tree_tag,tree_order_statistics_node_update> ordered_multiset;
typedef tree<pair<int, int>,null_type,greater<pair<int, int>>,rb_tree_tag,tree_order_statistics_node_update> ordered_multisetr;
//debug
template<typename F,typename S>ostream&operator<<(ostream&os,const pair<F,S>&p){return os<<"("<<p.first<<", "<<p.second<<")";}
template<typename T>ostream&operator<<(ostream&os,const vector<T>&v){os<<"{";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<*it;}return os<<"}";}
template<typename T>ostream&operator<<(ostream&os,const set<T>&v){os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<",";os<<*it;}return os<<"]";}
template<typename T>ostream&operator<<(ostream&os,const multiset<T>&v) {os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<*it;}return os<<"]";}
template<typename F,typename S>ostream&operator<<(ostream&os,const map<F,S>&v){os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<it->first<<" = "<<it->second;}return os<<"]";}
#define dbg(args...) do {cerr << #args << " : "; faltu(args); } while(0)
void faltu(){cerr << endl;}
template<typename T>void faltu(T a[],int n){for(int i=0;i<n;++i)cerr<<a[i]<<' ';cerr<<endl;}
template<typename T,typename...hello>void faltu(T arg,const hello&...rest){cerr<<arg<<' ';faltu(rest...);}
//#else
//#define dbg(args...)
/// Modular arithmetic
inline void normal(ll &a) { a %= MOD; (a < 0) && (a += MOD); }
inline ll modMul(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); return (a*b)%MOD; }
inline ll modAdd(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); return (a+b)%MOD; }
inline ll modSub(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); a -= b; normal(a); return a; }
inline ll modPow(ll b, ll p) { ll r = 1; while(p) { if(p&1) r = modMul(r, b); b = modMul(b, b); p >>= 1; } return r; }
inline ll modInverse(ll a) { return modPow(a, MOD-2); } /// When MOD is prime.
inline ll modDiv(ll a, ll b) { return modMul(a, modInverse(b)); }
/// Geometry section.
//*********************************************** The END **********************************************************************************************************************************
const ll N = 2e5 + 27;
const ll INF = 1e18;
const ld EPS = 1e-9;
const ll limit = (1LL<<32) - 1;
const ll K = N*N;
/// --------------------------------------------------------------
void Solution ( int tc ){
int n , m;
cin >> n >> m;
ll arr[n+1];
for ( int i = 1 ; i<=n ; ++i ) cin >> arr[i];
vector < tuple < ll , ll , ll > > v;
for ( int i = 1 ; i<=n ; ++i ) {
for ( int j = i + 1 ; j<=n ; ++j ) {
v.push_back ( { arr[i]+arr[j] , i , j } );
}
}
sort ( all ( v ) );
for ( auto it : v ){
ll x , i1,i2;
tie(x,i1,i2) = it;
tuple<ll,ll,ll> tm = { m - x , 0 , 0 };
ll ind = lower_bound( all(v) , tm ) - v.begin();
int cnt = 5;
while(cnt-- and ind < n*n ){
ll y , j1,j2;
tie(y,j1,j2) = v[ind];
if ( y == m - x and j1!=i1 and j1!=i2 and j2!=i1 and j2!=i2 ) {
cout << i1 << " " << i2 << " " << j1 << " " << j2 << "\n";
return;
}
}
}
cout << "IMPOSSIBLE\n";
return;
}
int main()
{
MUHAMMAD;
// AE;
/*
#ifdef OJ
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
*/
int testcase = 1 , tc = 0;
/// cin >> testcase;
for ( int i = 1 ; i <= testcase ; ++i ){
Solution( ++tc );
}
return 0;
}
/// __mhs, Do you check
/// -> overflow ?
/// -> array bound ?
/*
Explanation:
Time :
----------------------------------------------------------------------------------------------------------------
Alhamdulillah
*/