Submission #414943

#	Time	Username	Problem	Language	Result	Execution time	Memory
414943		Ruxandra985	Joker (BOI20_joker)	C++14	0 / 100	2068 ms	8148 KiB

Joker

#include <bits/stdc++.h>
#define DIMN 400010
using namespace std;
int tt[DIMN];
int sz[DIMN] , opt[DIMN];
int n , m , where;
pair <int , int> mch[DIMN];
vector <pair <int , int> > s;
vector <int> v;

int root (int x){
    while (tt[x] != x)
        x = tt[x];
    return x;
}

inline void unite (int x, int y){
    int radx = x, rady = y;
    if (sz[radx] < sz[rady])
        swap (radx,rady);

    s.push_back(make_pair(radx,rady)); /// stiva pt undo
    sz[radx] += sz[rady];
    tt[rady] = radx;
}

inline int unite_init (int x , int y){
    int radx = root(x) , radnx , rady = root(y) , radny;

    if (radx == rady)
        return 0;

    radnx = root(n + x);
    radny = root(n + y);

    unite(radx , radny);
    unite(rady , radnx);

    return 1;


}

void solve (int st , int dr , int l , int r , int ok){
    int mid = (st + dr)/2 , i , poz , x , y , init , init2 , now = ok;

    //printf ("%d %d\n" , st , dr);

    init = s.size();

    for (i = min(dr , m) ; i >= mid ; i--)
        now &= unite_init(mch[i].first , mch[i].second);

    if (!now){ /// din start nu e ok
        opt[mid] = l; /// care clar va fi 0
        poz = l;
    }
    else {
        poz = l;
        for (i = l + 1 ; i <= r && i < mid ; i++){

            x = mch[i].first;
            y = mch[i].second;

            if (!unite_init(x , y))
                break;

            poz = i;

        }
        opt[mid] = poz;
    }

    while (s.size() != init){

        x = s.back().first, y = s.back().second;
        s.pop_back();
        sz[x] -= sz[y];
        tt[y] = y;

    }

    now = ok;

    for (i = min(dr , m) ; i >= mid ; i--)
        now &= unite_init(mch[i].first , mch[i].second);



    if (st <= mid - 1)
        solve (st , mid - 1 , l , poz , now);

    while (s.size() != init){

        x = s.back().first, y = s.back().second;
        s.pop_back();
        sz[x] -= sz[y];
        tt[y] = y;

    }

    now = ok;

    if (mid + 1 <= dr){

        for (i = l + 1 ; i <= poz ; i++){
            x = mch[i].first;
            y = mch[i].second;
            now &= unite_init (x , y);
            //v.push_back(i);

        }

        solve(mid + 1 , dr , poz , r , now);

        while (s.size() != init){

            x = s.back().first, y = s.back().second;
            s.pop_back();
            sz[x] -= sz[y];
            tt[y] = y;

        }
    }

    /// convine sa te duci mai intai in dreapta, pastrezi tot ce ai adaugat
}

int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int q , i , l , r;
    fscanf (fin,"%d%d%d",&n,&m,&q);
    for (i = 1 ; i <= m ; i++){
        fscanf (fin,"%d%d",&mch[i].first,&mch[i].second);
    }

    /// opt se calculeaza intre 1 si M + 1

    for (i = 1 ; i <= 2 * n ; i++){
        tt[i] = i;
        sz[i] = 1;
    }

    solve (1 , m + 1 , 0 , m , 1); /// te asiguri ca dreapta nu cauzeaza ciclu impar

    for (;q;q--){
        fscanf (fin,"%d%d",&l,&r);
        if (opt[r + 1] >= l - 1 && r + 1 > where)
            fprintf (fout,"NO\n");
        else fprintf (fout,"YES\n");
    }
    return 0;
}

Compilation message (stderr)

Joker.cpp: In function 'void solve(int, int, int, int, int)':
Joker.cpp:74:21: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   74 |     while (s.size() != init){
      |            ~~~~~~~~~^~~~~~~
Joker.cpp:93:21: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   93 |     while (s.size() != init){
      |            ~~~~~~~~~^~~~~~~
Joker.cpp:116:25: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  116 |         while (s.size() != init){
      |                ~~~~~~~~~^~~~~~~
Joker.cpp:45:54: warning: unused variable 'init2' [-Wunused-variable]
   45 |     int mid = (st + dr)/2 , i , poz , x , y , init , init2 , now = ok;
      |                                                      ^~~~~
Joker.cpp: In function 'int main()':
Joker.cpp:134:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |     fscanf (fin,"%d%d%d",&n,&m,&q);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:136:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |         fscanf (fin,"%d%d",&mch[i].first,&mch[i].second);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:149:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  149 |         fscanf (fin,"%d%d",&l,&r);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 8
• Subtask 3: 0 / 25
• Subtask 4: 0 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29