Submission #998699

#	Time	Username	Problem	Language	Result	Execution time	Memory
998699		yeediot	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	100 / 100	585 ms	70084 KiB

joitter2

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
#ifdef local
void CHECK();
void setio(){
    freopen("/Users/iantsai/cpp/input.txt","r",stdin);
    freopen("/Users/iantsai/cpp/output.txt","w",stdout);
}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
#define TOI_is_so_de ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);setio();
const int mxn = 1e5+5;
int n, m, ans;
struct DSU{
    int to[mxn], num[mxn];
    set<int> g[mxn], out[mxn], in[mxn];
    queue<pii> to_merge;
    void init(){
        ans = 0;
        for(int i=1;i<=n;i++){
            g[i].clear();
            out[i].clear();
            in[i].clear();
            g[i].insert(i);
            num[i] = 1;
            to[i] = i;
        }
    }
    int find(int x){
        return x == to[x] ? x : to[x] = find(to[x]);
    }
    void merge(int x,int y){
        x = find(x);
        y = find(y);
        if(x == y){
            return ;
        }
        if(sz(g[x]) > sz(g[y])){
            swap(x, y);
        }
        ans = ans+num[x]*sz(g[y])+num[y]*sz(g[x]);
        for(auto u:g[x]){
            if(g[y].count(u)){
                ans -= num[x]+num[y];
            }
            else{
                g[y].insert(u);
            }
        }
        to[x] = y;
        num[y] += num[x];
        in[x].erase(y);
        in[y].erase(x);
        out[x].erase(y);
        out[y].erase(x);
        for(auto v : in[x]){
            out[v].erase(x);
            add(v, y);
        }
        for(auto v : out[x]){
            in[v].erase(x);
            add(y, v);
        }
    }
    void add(int x, int y){
        in[y].insert(x);
        out[x].insert(y);
        if(out[y].count(x)){
            to_merge.push({x, y});
        }
    }
    void cal(int x, int y){
        int px = find(x), py = find(y);
        y = py;
        if(px!=py and !g[y].count(x)){
            g[y].insert(x);
            ans += num[y];
            x = px;
            add(x, y);
            while(sz(to_merge)){
                auto [v, u] = to_merge.front();
                to_merge.pop();
                merge(v, u);
            }
        }
    }
}d;
signed main(){
    TOI_is_so_de;
    cin >> n >> m;
    d.init();
    for(int i=0;i<m;i++){
        int x, y;
        cin >> x >> y;
        d.cal(x, y);
        cout << ans << '\n';
    }
    #ifdef local
    CHECK();
    #endif
}
/*
input:
 
*/
#ifdef local
void CHECK(){
    cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
     function<bool(string,string)> compareFiles = [](string p1, string p2)->bool {
         std::ifstream file1(p1);
         std::ifstream file2(p2);
         if (!file1.is_open() || !file2.is_open())return false;
         std::string line1, line2;
         while (getline(file1, line1) && getline(file2, line2)) {
             if (line1 != line2)return false;
         }
         int cnta=0,cntb=0;
         while(getline(file1,line1))cnta++;
         while(getline(file2,line2))cntb++;
         return cntb-cnta<=1;
     };
     bool check = compareFiles("output.txt","expected.txt");
     if (check) cerr<<"ACCEPTED\n";
     else cerr<<"WRONG ANSWER!\n";
}
#else
#endif



 

Compilation message (stderr)

joitter2.cpp: In function 'void setIO(std::string)':
joitter2.cpp:35:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joitter2.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 83 / 83