Submission #1201964

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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++)
#define ALL(x) x.begin(),x.end()
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 connect(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,X,Y;
pair<int,int> colorMin [200001];
ll fact [200001],rfact [200001];
const int INF = 2e9;
const ll MOD = 1e9 + 7;

ll mod_pow(ll x,ll y = MOD - 2)
{
	ll res = 1;
	while(y){
		if(y & 1) (res *= x) %= MOD;
		(x *= x) %= MOD;
		y >>= 1;
	}
	return res;
}

int main()
{
	scanf("%d%d%d",&N,&X,&Y);
	vector<int> C(N),W(N);
	fill(colorMin + 1,colorMin + N + 1,make_pair(INF,0));
	FOR(i,0,N){
		scanf("%d%d",&C [i],&W [i]);
		chmin(colorMin [C [i]],make_pair(W [i],i));
	}

	if(count(colorMin + 1,colorMin + N + 1,make_pair(INF,0)) >= N - 1){
		printf("1\n");
		return 0;
	}
	sort(colorMin + 1,colorMin + N + 1);
	
	UnionFind uf(N);
	FOR(i,0,N){
		if(C [i] == C [colorMin [1].second]){
			if(W [i] + W [colorMin [1].second] <= X){
				uf.connect(i,colorMin [1].second);
			}
		}
		else{
			if(W [i] + W [colorMin [1].second] <= Y){
				uf.connect(i,colorMin [1].second);
			}
		}
		if(C [i] == C [colorMin [2].second]){
			if(W [i] + W [colorMin [2].second] <= X){
				uf.connect(i,colorMin [2].second);
			}
		}
		else{
			if(W [i] + W [colorMin [2].second] <= Y){
				uf.connect(i,colorMin [2].second);
			}
		}
	}

	map<int,int> mp;
	FOR(i,0,N) if(uf.same(i,colorMin [1].second)){
		mp [C [i]]++;
	}

	fact [0] = rfact [0] = 1;
	for(int i = 1;i <= 200000;i++){
		fact [i] = fact [i - 1] * i % MOD;
		rfact [i] = mod_pow(fact [i]);
	}
	ll ans = 1,sum = 0;
	for(const auto& it : mp){
		(ans *= rfact [it.second]) %= MOD;
		sum += it.second;
	}
	(ans *= fact [sum]) %= MOD;

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

	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:51:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&N,&X,&Y);
                          ^
./Main.cpp:55:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&C [i],&W [i]);
                              ^

Judge Result