Submission #1269860

#	Time	Username	Problem	Language	Result	Execution time	Memory
1269860		herominhsteve	Bosses (BOI16_bosses)	C++20	100 / 100	377 ms	752 KiB

bosses

#include <bits/stdc++.h>
#define el '\n'
#define FNAME "bosses"
#define allof(x) x.begin(),x.end()
#define allof1(x) x.begin()+1,x.end()
#define mset(x,n) memset(x,(n),sizeof(x))
using namespace std;
const long long MOD = (long long) 1e9+7;
template<class X,class Y> bool minimize(X &a,Y b){ if (a>b) {a=b; return true;} return false;}
template<class X,class Y> bool maximize(X &a,Y b){ if (a<b) {a=b; return true;} return false;}

void setup(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
	if (fopen(FNAME".inp","r")){
		freopen(FNAME".inp","r",stdin);
		freopen(FNAME".out","w",stdout);
	}
}

const int MAXN = 5005;
const long long INF = (long long) 1e15 + 15092007;

int n;
vector<int> graph[MAXN];

void init(){
	cin>>n;
	for (int u=1;u<=n;u++){
		int k;
		cin>>k;
		for (int i=0;i<k;i++){
			int p;
			cin>>p;
			graph[p].push_back(u);
		}
	}
}

long long bfs(int s){
	vector<long long> distancia(n+1,-1);
	queue<int> qu;
	qu.push(s);
	distancia[s] = 1;
	while (!qu.empty()){
		int u = qu.front(); qu.pop();
		for (int v : graph[u]){
			if (distancia[v]==-1){
				distancia[v] = distancia[u] + 1;
				qu.push(v);
			}
		}
	}
	long long res = 0;
	for (int u=1;u<=n;u++){
		if (distancia[u]==-1) return INF;
		res += distancia[u];
	}
	return res;
}

void sol(){
	long long res = INF;
	for (int u=1;u<=n;u++) minimize(res,bfs(u));
	cout<< (res==INF ? -1 : res);
}

int main(){
    setup();
    init();
    sol();
}

Compilation message (stderr)

bosses.cpp: In function 'void setup()':
bosses.cpp:16:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |                 freopen(FNAME".inp","r",stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:17:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |                 freopen(FNAME".out","w",stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 33 / 33