Submission #676820

#	Time	Username	Problem	Language	Result	Execution time	Memory
676820		DwightKSchrute	Event Hopping 2 (JOI21_event2)	C++17	7 / 100	75 ms	10316 KiB

event2

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
 */
#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int>vi;
typedef vector<vector<int>>vvi;
typedef vector<ll>vl;
typedef vector<vl> vvl;
typedef pair<int,int>pi;
typedef pair<ll,ll> pl;
typedef vector<pl> vpl;
typedef vector<ld> vld;
typedef pair<ld,ld> pld;
typedef vector<pi> vpi;

//typedef tree<ll, null_type, less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
template<typename T> ostream& operator<<(ostream& os, vector<T>& a){os<<"[";for(int i=0; i<ll(a.size()); i++){os << a[i] << ((i!=ll(a.size()-1)?" ":""));}os << "]\n"; return os;}

#define all(x) x.begin(),x.end()
#define YES out("YES")
#define NO out("NO")
#define out(x){cout << x << "\n"; return;}
#define outfl(x){cout << x << endl;return;}
#define GLHF ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define print(x){for(auto ait:x) cout << ait << " "; cout << "\n";}
#define pb push_back
#define umap unordered_map


template<typename T>
void read(vector<T>& v){
    int n=v.size();
    for(int i=0; i<n; i++)
        cin >> v[i];
}
template<typename T>
vector<T>UNQ(vector<T>a){
    vector<T>ans;
    for(T t:a)
        if(ans.empty() || t!=ans.back())
            ans.push_back(t);
    return ans;
}



void solve();
int main(){
    GLHF;
    int t=1;
    //cin >> t;
    while(t--)
        solve();
}
void compress(vvi& a){
    vi s;
    for(vi v:a)
        s.pb(v[0]),s.pb(v[1]);
    sort(all(s));
    for(vi& v:a){
        v[0] = lower_bound(all(s),v[0])-s.begin();
        v[1] = lower_bound(all(s),v[1])-s.begin();
    }
}
void solve() {
    int n,k;
    cin >> n >> k;
    vvi a(n,vi(3));
    for(int i=0; i<n ;i++){
        cin >> a[i][0] >> a[i][1];
        a[i][1]--;
        a[i][2]=i;
    }
    compress(a);
    //sort(all(a));

    vi dp(n),suff_mx(n+1),to(n+1);
    for(int i=n-1; i>=0; i--){
        dp[i]=1;
        int l=a[i][0],r=a[i][1];
        int nxt = lower_bound(a.begin()+i,a.end(),(vi){r+1,-1,-1})-a.begin();
        if(nxt<n)
            dp[i] = max(dp[i],1+suff_mx[nxt]);
        to[i] = nxt;
        suff_mx[i] = max(dp[i],suff_mx[i+1]);
    }
    if(dp[0]<k)out(-1)
    vi ans;
    for(int i=0; i<n; )
        if(dp[i]>=k && k)
            ans.pb(i+1),k--,i=to[i];
        else
            i++;

    for(int x:ans)
        cout << x << "\n";
}

Compilation message (stderr)

event2.cpp: In function 'void solve()':
event2.cpp:91:13: warning: unused variable 'l' [-Wunused-variable]
   91 |         int l=a[i][0],r=a[i][1];
      |             ^

• Subtask 1: 7 / 7
• Subtask 2: 0 / 1
• Subtask 3: 0 / 31
• Subtask 4: 0 / 61