Submission #1357686

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

#define FOR(i,l,r) for(int i = (int) (l);i < (int) (r);i++)
template<typename T> bool chmax(T& a,const T& b){ return a < b ? (a = b,true) : false; }
template<typename T> bool chmin(T& a,const T& b){ return b < a ? (a = b,true) : false; }
typedef long long ll;

struct UnionFind{
	vector<int> par,rank;
	UnionFind(int n) :par(n + 1),rank(n + 1,1){
		for(int i = 1;i <= n;i++) par [i] = i;
	}
	int find(int x){
		return par [x] == x ? x : par [x] = find(par [x]);
	}
	bool unite(int x,int y){
		x = find(x);
		y = find(y);
		if(x == y) return false;
		if(rank [x] < rank [y]) swap(x,y);
		rank [x] += rank [x] == rank [y];
		par [y] = x;
		return true;
	}
	bool same(int x,int y){
		return find(x) == find(y);
	}
};

int N,M;
const int MAX_N = 16;
bool G [MAX_N] [MAX_N];

int main()
{
	scanf("%d%d",&N,&M);
	FOR(i,0,M){
		int u,v;
		scanf("%d%d",&u,&v);
		G [u - 1] [v - 1] = true;
		G [v - 1] [u - 1] = true;
	}

	int ans = 0;
	FOR(mask,0,1 << N){
		int cnt = 1;
		UnionFind uf(N);
		FOR(i,0,N) FOR(j,0,N) if((mask >> i & 1) ^ (mask >> j & 1)){
			if(G [i] [j]){
				cnt += uf.unite(i,j);
			}
		}
		ans += cnt == N;
	}
	ans /= 2;

	printf("%d\n",ans);

	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:37:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&M);
                     ^
./Main.cpp:40:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&u,&v);
                      ^

Judge Result