Submission #1225590

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Source Code Expand

#include <cstdio>
#include <iostream>
using namespace std;
#define DEBUG(X) cerr<<__LINE__<<" "<<#X<<": "<<X<<endl;
#define sci(x) int x;scanf("%d",&x);
#define scii(x, y) int x,y;scanf("%d%d",&x,&y);
struct UFTree {
  int par[1000010];  // 親
  int rank[1000010]; // 木の深さ

  UFTree(int n){
    for(int i=0;i<n;i++){
      par[i] = i;
      rank[i] = 0;
    }
  }
  int root(int a){
    if (par[a] == a) return a;
    else return par[a] = root(par[a]);
  }

  bool unite(int a,int b){
    a=root(a);
    b=root(b);
    if(a==b) return false;
    if (rank[a] < rank[b])
      par[a] = b;
    else {
      par[b] = a;
      if (rank[a] == rank[b]) rank[a]++;
    }
    return true;
  }

  bool same(int a,int b) {
    return root(a) == root(b);
  }
};

int main() {
  scii(N, M)
  UFTree tree(N);
  for (int i=0;i<M;i++) {
    scii(a,b);
    tree.unite(a,b);
  }
  int ans = 0;
  for (int j=0;j<N;j++) {
    if (tree.par[j]==j) ans++;
  }
  printf("%d\n",--ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:6:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
 #define scii(x, y) int x,y;scanf("%d%d",&x,&y);
                                               ^
./Main.cpp:41:3: note: in expansion of macro ‘scii’
   scii(N, M)
   ^
./Main.cpp:6:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
 #define scii(x, y) int x,y;scanf("%d%d",&x,&y);
                                               ^
./Main.cpp:44:5: note: in expansion of macro ‘scii’
     scii(a,b);
     ^

Judge Result