Submission #1009007

#	Time	Username	Problem	Language	Result	Execution time	Memory
1009007		GrindMachine	Spy 3 (JOI24_spy3)	C++17	92 / 100	142 ms	12984 KiB

Aoi

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*

refs:
https://codeforces.com/blog/entry/127315?#comment-1131129

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "Aoi.h"

namespace {

    int variable_example = 0;

    int function_example(int a, int b) { return a + b; }

}  // namespace

std::string aoi(int n, int m, int q, int k, std::vector<int> A,
                std::vector<int> B, std::vector<long long> C,
                std::vector<int> T, std::vector<int> X) {
    
    // n = #of nodes, m = #of edges
    // A,B,C = edges of graph
    // q = #of query cities
    // T = query cities
    // k = #of deleted edges
    // X = ids of deleted edges

    vector<pll> adj1[n];
    vector<vector<ll>> adj2(n);
    map<pll,ll> mp;

    rep(i,m){
        ll u = A[i], v = B[i], w = C[i];
        adj1[u].pb({v,w}), adj1[v].pb({u,w});
        mp[{u,v}] = mp[{v,u}] = i;
    }

    // build sp tree
    priority_queue<array<ll,3>,vector<array<ll,3>>,greater<array<ll,3>>> pq;
    pq.push({0,0,-1});
    vector<ll> par(n,-1);
    vector<bool> vis(n);
    vector<ll> depth(n);

    while(!pq.empty()){
        auto [dis,u,p] = pq.top();
        pq.pop();

        if(vis[u]) conts;
        vis[u] = 1;
        par[u] = p;
        if(p != -1){
            depth[u] = depth[p]+1;
            adj2[p].pb(u);
        }

        // cout << p << " " << u << endl;

        for(auto [v,w] : adj1[u]){
            pq.push({dis+w,v,u});
        }
    }

    // calc tin,tout
    vector<ll> tin(n), tout(n);
    ll timer = 0;

    auto dfs1 = [&](ll u, auto &&dfs1) -> void{
        tin[u] = timer++;
        trav(v,adj2[u]){
            dfs1(v,dfs1);
        }
        tout[u] = timer-1;
    };

    dfs1(0,dfs1);

    auto is_ances = [&](ll u, ll v){
        return tin[u] <= tin[v] and tout[u] >= tout[v];
    };

    auto get_lca = [&](ll u, ll v){
        // cout << u << " " << v << " ";
        while(u != v){
            if(depth[u] < depth[v]) swap(u,v);
            u = par[u];
        }

        // cout << u << endl;
        return u;
    };

    // find the nodes of the virtual tree
    vector<pll> nodes;
    nodes.pb({0,0});
    rep(i,q){
        ll u = T[i];
        nodes.pb({tin[u],u});
    }

    sort(all(nodes));
    nodes.resize(unique(all(nodes))-nodes.begin());
    ll initial_size = sz(nodes);

    rep(i,initial_size-1){
        ll lca = get_lca(nodes[i].ss,nodes[i+1].ss);
        nodes.pb({tin[lca],lca});
    }

    sort(all(nodes));
    nodes.resize(unique(all(nodes))-nodes.begin());
    assert(sz(nodes) <= 2*q);

    // for(auto [ti,u] : nodes){
    //     cout << ti << " " << u << endl;
    // }
    
    // build the virtual tree + construct walk
    stack<ll> stk;
    vector<ll> pv(n,-1);
    vector<ll> node_id(n,-1);
    stk.push(0);
    node_id[0] = 0;
    string walk = "";
    ll ptr = 1;
    rep1(i,sz(nodes)-1){
        ll u = nodes[i].ss;
        node_id[u] = ptr++;
        while(!is_ances(stk.top(),u)){
            stk.pop();
            walk.pb('0');
        }
        pv[u] = stk.top();
        stk.push(u);
        walk.pb('1');
    }

    while(!stk.empty()){
        stk.pop();
        walk.pb('0');
    }
    assert(sz(walk) == 2*sz(nodes)-1);
    
    // for each edge in the sp tree, find the virtual edge that it belongs to
    vector<ll> idv(m,2*q-1);
    rep1(i,sz(nodes)-1){
        ll u = nodes[i].ss;
        ll incoming_edge = node_id[u]-1;
        assert(incoming_edge >= 0);
        ll ppv = pv[u];

        while(u != ppv){
            ll p = par[u];
            ll id = mp[{u,p}];
            idv[id] = incoming_edge;
            u = p;
        }
    }

    // for each deleted edge, encode the edge in the virtual tree that it belongs to
    string edge_encoding = "";
    rep(i,k){
        ll curr_id = idv[X[i]];
        rev(bit,4,0){
            ll b = 0;
            if(curr_id&(1<<bit)) b = 1;
            edge_encoding.pb(char('0'+b));
        }
    }

    // for each query node, encode it's corresponding node in the virtual tree
    string node_encoding = "";
    rep(i,q){
        ll curr_id = node_id[T[i]];
        assert(curr_id != -1);

        rev(bit,4,0){
            ll b = 0;
            if(curr_id&(1<<bit)) b = 1;
            node_encoding.pb(char('0'+b));
        }
    }

    string s = walk+edge_encoding+node_encoding;
    return s;

    // string s = "";

    // rep(i,q){
    //     ll u = T[i];
    //     vector<ll> path;
    //     while(u){
    //         path.pb(u);
    //         u = par[u];
    //     }
    //     path.pb(0);
        
    //     vector<ll> edges;
    //     rep(j,sz(path)-1){
    //         pll px = {path[j],path[j+1]};
    //         edges.pb(mp[px]);
    //     }

    //     sort(all(edges));

    //     rep(j,k){
    //         ll id = X[j];
    //         if(binary_search(all(edges),id)){
    //             s.pb('1');
    //         }
    //         else{
    //             s.pb('0');
    //         }
    //     }
    // }

    // return s;

    // variable_example++;
    // variable_example = function_example(1, 2);
    // std::string s(100, '0');
    // s[0] = '1';
    // return s;
}

Bitaro

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*

refs:
https://codeforces.com/blog/entry/127315?#comment-1131129

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "Bitaro.h"

namespace {

    int variable_example = 0;

    int function_example(int a, int b) { return a + b; }

}  // namespace

void bitaro(int n, int m, int q, int k, std::vector<int> A, std::vector<int> B,
            std::vector<long long> C, std::vector<int> T, std::vector<int> X,
            std::string s) {

    // n = #of nodes, m = #of edges
    // A,B,C = edges of graph (edge weights of deleted edges = -1)
    // q = #of query cities
    // T = query cities
    // k = #of deleted edges
    // X = ids of deleted edges
    // s = received string

    vector<pll> adj[n];
    map<pll,ll> mp;

    rep(i,m){
        ll u = A[i], v = B[i], w = C[i];
        adj[u].pb({v,w}), adj[v].pb({u,w});
        mp[{u,v}] = mp[{v,u}] = i;
    }

    // recover the walk
    ll ptr = 0;
    stack<ll> stk;
    vector<ll> pv;
    pv.pb(-1);
    ll curr_node = 0;

    while(curr_node != -1){
        char ch = s[ptr++];
        if(ch == '1'){
            pv.pb(curr_node);
            curr_node = sz(pv)-1;
        }
        else{
            curr_node = pv[curr_node];
        }
    }

    // recover the virtual edge that each deleted edge belongs to
    vector<ll> idv(k,-1);
    rep(i,k){
        ll mask = 0;
        rep(bit,5){
            mask = (mask<<1)|(s[ptr++]-'0');
        }

        idv[i] = mask;
    }

    rep(i,q){
        // recover the corresponding node of T[i] in the virtual tree
        ll src = 0;
        rep(bit,5){
            src = (src<<1)|(s[ptr++]-'0');
        }

        vector<bool> good(2*q);
        ll curr_node = src;

        while(curr_node){
            good[curr_node-1] = 1;
            curr_node = pv[curr_node];
        }

        vector<bool> spl(n); 
        vector<bool> on_path(m);

        rep(j,k){
            ll id = X[j];
            if(good[idv[j]]){
                on_path[id] = 1;
                spl[A[id]] = spl[B[id]] = 1;
            }
        }

        rep(j,q){
            spl[T[j]] = 1;
        }

        priority_queue<array<ll,3>,vector<array<ll,3>>,greater<array<ll,3>>> pq;
        pq.push({0,0,-1});
        vector<ll> par(n,-1);
        vector<bool> vis(n);

        while(!pq.empty()){
            auto [dis,u,p] = pq.top();
            pq.pop();

            if(vis[u]) conts;
            vis[u] = 1;
            par[u] = p;

            if(spl[u]){
                ll cnt = 0;
                for(auto [v,w] : adj[u]){
                    ll id = mp[{u,v}];
                    if(w == -1 and on_path[id]){
                        cnt++;
                    }
                }

                if(cnt){
                    while(!pq.empty()){
                        pq.pop();
                    }   

                    for(auto [v,w] : adj[u]){
                        ll id = mp[{u,v}];
                        if(w == -1 and on_path[id]){
                            on_path[id] = 0;
                            pq.push({0,v,u});
                        }
                    }

                    conts;
                }
            }

            for(auto [v,w] : adj[u]){
                if(w == -1) conts;
                pq.push({dis+w,v,u});
            }
        }

        vector<ll> nodes;
        ll u = T[i];
        while(u){
            assert(u != -1);
            nodes.pb(u);
            u = par[u];
        }
        nodes.pb(0);
        reverse(all(nodes));

        vector<int> ans;
        rep(j,sz(nodes)-1){
            pll px = {nodes[j],nodes[j+1]};
            ans.pb(mp[px]);
        }

        answer(ans);

        // trav(x,ans) cout << x << " ";
        // cout << endl;
    }

    // variable_example++;
    // variable_example = function_example(1, 2);
    // for (int i = 0; i < q; i++) {
    //     std::vector<int> v(10);
    //     for (int j = 0; j < 10; j++) {
    //         v[j] = j;
    //     }
    //     answer(v);
    // }
}

Compilation message (stderr)

Aoi.cpp:67:9: warning: 'int {anonymous}::function_example(int, int)' defined but not used [-Wunused-function]
   67 |     int function_example(int a, int b) { return a + b; }
      |         ^~~~~~~~~~~~~~~~
Aoi.cpp:65:9: warning: '{anonymous}::variable_example' defined but not used [-Wunused-variable]
   65 |     int variable_example = 0;
      |         ^~~~~~~~~~~~~~~~

Bitaro.cpp:67:9: warning: 'int {anonymous}::function_example(int, int)' defined but not used [-Wunused-function]
   67 |     int function_example(int a, int b) { return a + b; }
      |         ^~~~~~~~~~~~~~~~
Bitaro.cpp:65:9: warning: '{anonymous}::variable_example' defined but not used [-Wunused-variable]
   65 |     int variable_example = 0;
      |         ^~~~~~~~~~~~~~~~

• Subtask 1: 92 / 100