题意:中文题。。不写了
思路:优先对列,小的优先
AC代码:
#include "iostream" #include "string.h" #include "stack" #include "queue" #include "string" #include "vector" #include "set" #include "map" #include "algorithm" #include "stdio.h" #include "math.h" #define ll long long #define bug(x) cout<<x<<" "<<"UUUUU"<<endl; #define mem(a) memset(a,0,sizeof(a)) #define mp(x,y) make_pair(x,y) #define pb(x) push_back(x) using namespace std; const long long INF = 1e18+1LL; const int inf = 1e9+1e8; const int N=1e6+100; const ll mod=1e9+7; int n,m,pre[N]; void init(int n){ for(int i=0; i<=n; ++i) pre[i]=i; } int finds(int x){ return pre[x]=pre[x]==x?x:finds(pre[x]); } void unions(int x, int y){ int fx=finds(x), fy=finds(y); pre[fy]=fx; } int main(){ ios::sync_with_stdio(false),cin.tie(0),cout.tie(0); cin>>n>>m; init(2*n); int t,a,b; for(int i=1; i<=m; ++i){ cin>>t>>a>>b; if(t==1){ unions(a, b); unions(a+n, b+n); } else{ unions(a, b+n); unions(b, a+n); } } for(int i=1; i<=n; ++i){ int fi=finds(i), fn=finds(i+n); if(fi==fn){ cout<<"NO "; return 0; } } cout<<"YES "; return 0; }