oj.uz

답안 #43272

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
43272 2018-03-12T13:00:05 Z ffresh 우호 조약 체결 (JOI14_friends) C++14
35 / 100
 127 ms 8156 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 1e5+15;

int par[N],sz[N],esz[N];

vector<int> adj[N];

int f(int a){
	if(a==par[a])return a;
	return par[a]= f(par[a]);
}
void merge(int a,int b){
	a= f(a),b= f(b);
	if(a!=b){
		par[b]= a;
		sz[a]+=sz[b];
		esz[a]+=esz[b];
	}
	++esz[a];
}
bool vis[N];

void dfs(int root){
	vis[root]= 1;
	for(int i=0;i<adj[root].size();++i){
		int u = adj[root][i];
		if(!vis[u]){
			dfs(u);
		}
		merge(u,root);
	}
}


int main(){
	//freopen("input.txt","r",stdin);
	int n,m,a,b;
	scanf("%d%d",&n,&m);
	assert(n<=1e5);
	for(int i=0;i<m;++i){
		scanf("%d%d",&a,&b);
		adj[a].push_back(b);
	}
	for(int i=1;i<=n;++i)
		par[i] =i,sz[i]= 1;
	for(int i=1;i<=n;++i){
		if((int)adj[i].size()>=2){
			int cur = adj[i][0],v;
			for(int j=0;j<adj[i].size();++j){
				int u = adj[i][j];
				if(!vis[u])
					dfs(u);
				if(f(u)!=f(cur)){
					v = f(cur),u = f(u);
					par[u] = v;
					esz[v]+=esz[u];
					sz[v] += sz[u];
				}
			}
		}
	}
	
	long long ret=0;
	for(int i=1;i<=n;++i){
		if(f(i)==i){
			ret += (long long)(sz[i]*(sz[i]-1));
			ret -= esz[i];
		}
	}
	ret+=m;
	cout<<ret<<endl;
}

Compilation message

friends.cpp: In function 'void dfs(int)':
friends.cpp:28:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<adj[root].size();++i){
               ^
friends.cpp: In function 'int main()':
friends.cpp:52:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=0;j<adj[i].size();++j){
                 ^
friends.cpp:41:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
friends.cpp:44:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a,&b);
                      ^

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 2680 KB Output is correct
2 Correct 4 ms 2680 KB Output is correct
3 Correct 3 ms 2728 KB Output is correct
4 Correct 3 ms 2856 KB Output is correct
5 Correct 4 ms 2856 KB Output is correct
6 Correct 3 ms 2868 KB Output is correct
7 Correct 4 ms 2868 KB Output is correct
8 Correct 5 ms 2868 KB Output is correct
9 Correct 4 ms 2960 KB Output is correct
10 Correct 4 ms 2960 KB Output is correct
11 Correct 3 ms 2960 KB Output is correct
12 Correct 3 ms 2960 KB Output is correct
13 Correct 3 ms 2960 KB Output is correct
14 Correct 3 ms 2960 KB Output is correct
15 Correct 4 ms 2988 KB Output is correct
16 Correct 3 ms 2988 KB Output is correct
17 Correct 3 ms 2988 KB Output is correct
18 Correct 4 ms 2988 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 3124 KB Output is correct
2 Correct 4 ms 3124 KB Output is correct
3 Correct 10 ms 3312 KB Output is correct
4 Correct 49 ms 4184 KB Output is correct
5 Correct 40 ms 4184 KB Output is correct
6 Correct 69 ms 4612 KB Output is correct
7 Correct 4 ms 4612 KB Output is correct
8 Correct 7 ms 4612 KB Output is correct
9 Correct 12 ms 4612 KB Output is correct
10 Correct 21 ms 4612 KB Output is correct
11 Correct 67 ms 4612 KB Output is correct
12 Correct 11 ms 4612 KB Output is correct
13 Correct 6 ms 4612 KB Output is correct
14 Correct 5 ms 4612 KB Output is correct
15 Correct 8 ms 4612 KB Output is correct
16 Correct 15 ms 4612 KB Output is correct
17 Correct 65 ms 4612 KB Output is correct
18 Correct 5 ms 4612 KB Output is correct
19 Correct 6 ms 4612 KB Output is correct
20 Correct 61 ms 4612 KB Output is correct
21 Correct 6 ms 4612 KB Output is correct
22 Correct 5 ms 4612 KB Output is correct
23 Correct 7 ms 4612 KB Output is correct
24 Correct 5 ms 4612 KB Output is correct
25 Correct 7 ms 4612 KB Output is correct
26 Correct 5 ms 4612 KB Output is correct
27 Correct 6 ms 4612 KB Output is correct
28 Correct 5 ms 4612 KB Output is correct

Subtask #3
0 / 65.0

# 결과 실행 시간 메모리 Grader output
1 Correct 72 ms 4612 KB Output is correct
2 Incorrect 127 ms 8156 KB Output isn't correct
3 Halted 0 ms 0 KB -