Submission #3008675

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Source Code Expand

#include <cstdio>
#include <vector>
#define repi(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,a) repi(i,0,a)
#define all(a) (a).begin(), (a).end()

int N, M;
std::vector<int> G[110];
bool used[110];
int ans;

bool dfs( int v, int prv )
{
  used[v] = true;

  for( auto &u : G[v] )
  {
    if( u != prv && used[u] )
      return false;

    if( !used[u] && !dfs( u, v ) )
      return false;
  }

  return true;
}

int main()
{
  scanf( "%d%d", &N, &M );
  rep( i, M )
  {
    int u, v;
    scanf( "%d%d", &u, &v );
    --u; --v; 
    G[u].emplace_back( v );
    G[v].emplace_back( u );
  }

  rep( i, N ) if( !used[i] )
    ans += dfs( i, -1 );

  printf( "%d\n", ans );
  
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:30:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf( "%d%d", &N, &M );
                          ^
./Main.cpp:34:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf( "%d%d", &u, &v );
                            ^

Judge Result