Submission #411506

#	Time	Username	Problem	Language	Result	Execution time	Memory
411506		Ruxandra985	Graph (BOI20_graph)	C++14	0 / 100	2 ms	2636 KiB

Graph

#include <bits/stdc++.h>
#define DIMN 100010
using namespace std;
double sol[DIMN];
int f[DIMN] , f2[DIMN];
vector <pair <int , int> > v[DIMN];
pair <int , int> cod[DIMN];
deque <int> dq;
int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int n , m , i , a , y , z , found , nod , vecin , tip;
    double x;
    fscanf (fin,"%d%d",&n,&m);
    for (i = 1 ; i <= m ; i++){
        fscanf (fin,"%d%d%d",&a,&y,&z);
        v[a].push_back(make_pair(y , z));
        v[y].push_back(make_pair(a , z));
    }

    for (int j = 1 ; j <= n ; j++){

        if (f[j])
            continue;

        cod[j] = make_pair(0 , j);
        dq.push_back(j);
        f[j] = 1;
        found = 0;

        while (!dq.empty() && !found){
            nod = dq.front();
            dq.pop_front();

            for (i = 0 ; i < v[nod].size() ; i++){
                vecin = v[nod][i].first;
                tip = v[nod][i].second;

                if (!f[vecin]){

                    dq.push_back(vecin);
                    f[vecin] = 1;

                    cod[vecin] = make_pair(tip - cod[nod].first , -cod[nod].second);

                }
                else {

                    /// momentul sa vezi daca relatiile sunt echivalente, contradictorii
                    /// sau daca sau solutia x

                    if (cod[vecin] == make_pair(tip - cod[nod].first , -cod[nod].second))
                        continue; /// echivalent

                    if (cod[vecin].second == -cod[nod].second && cod[vecin].first != tip - cod[nod].first){

                        fprintf (fout,"NO"); /// contradictorii
                        return 0;

                    }

                    if (cod[vecin].second != -cod[nod].second){

                        if (cod[vecin].second == 1){

                            x = 1.0 * (tip - cod[nod].first - cod[vecin].first) / 2;
                            found = 1;
                            break; /// ai aflat x

                        }
                        else {

                            x = 1.0 * (cod[vecin].first - tip + cod[nod].first) / 2;
                            found = 1;
                            break;

                        }

                    }

                }

            }

        }

        if (!found){
            x = 0;
            found = 1;
        }

        if (found){

            dq.clear();

            dq.push_back(j);
            f2[j] = 2;

            sol[j] = x;

            while (!dq.empty()){
                nod = dq.front();
                dq.pop_front();

                for (i = 0 ; i < v[nod].size() ; i++){
                    vecin = v[nod][i].first;
                    tip = v[nod][i].second;

                    if (f2[vecin] != 2){

                        dq.push_back(vecin);
                        f2[vecin] = 2;

                        sol[vecin] = tip - sol[nod];

                    }
                    else {

                        if (sol[vecin] != tip - sol[nod]){
                            fprintf (fout,"NO");
                            return 0;
                        }

                    }

                }

            }


        }
    }

    cout << "YES\n";
    for (i = 1 ; i <= n ; i++){
        cout << sol[i] << " ";
    }

    return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'int main()':
Graph.cpp:36:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |             for (i = 0 ; i < v[nod].size() ; i++){
      |                          ~~^~~~~~~~~~~~~~~
Graph.cpp:106:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |                 for (i = 0 ; i < v[nod].size() ; i++){
      |                              ~~^~~~~~~~~~~~~~~
Graph.cpp:15:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     fscanf (fin,"%d%d",&n,&m);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~
Graph.cpp:17:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         fscanf (fin,"%d%d%d",&a,&y,&z);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 12
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 42