Submission #19283982

---

Source Code Expand

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx")
#pragma GCC target ("avx2,fma")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <atcoder/all>

#define F first
#define S second
#define int long long
#define ll long long
//#define int  unsigned long long
#define pb push_back
#define rank fewfewf
#define double long double

using namespace std;
using namespace __gnu_pbds;
using namespace atcoder;


typedef  tree< int , null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1000000;
const int K = 20;
const int mod = 1e9 + 7;
int a[N], b[N], p[N], wh[N], cur[N];
main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("input.txt", "r", stdin);
    //freopen("input.txt", "w", stdout);
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }
    set<pair<int,pair<int,int>>> s;
    for (int i = 1; i <= n; i++){
        cin >> b[i];
    }
    for (int i = 1; i <= n; i++){
        cin >> p[i];
        s.insert({b[p[i]], {i, p[i]}});
        cur[i] = p[i];
        if (b[p[i]] >= a[i] && p[i] != i){
            cout << -1;
            return 0;
        }
    }
    vector<pair<int,int>> ans;
    while(!s.empty()){
        auto x = *s.rbegin();
        s.erase(prev(s.end()));
        int owner = x.S.F;
        int index = x.S.S;
        int weight = x.F;
        if (a[owner] <= weight && owner != index){
            cout << "-1";
            return 0;
        }
        if (owner == index){
            continue;
        }
        int sw = index;
        ans.pb({sw, owner});
        cur[owner] = cur[sw];
        s.erase({b[cur[sw]], {sw, cur[sw]}});
        s.insert({b[cur[sw]], {owner, cur[sw]}});
    }
    cout << ans.size() << endl;
    for (auto x: ans){
        cout << x.F << " " << x.S << '\n';
    }
}

Submission Info

Compile Error

./Main.cpp:30:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type]
   30 | main(){
      |      ^

Judge Result