Submission #1062273

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062273		nightfal	Stations (IOI20_stations)	C++17	5 / 100	650 ms	944 KiB

stations

#include <vector>
#include <iostream>
using namespace std;

template <typename T> void print(T elem) {cout << elem << " ";}
template <typename T> void print(vector<T> &v) {for(auto elem: v) print(elem); cout << endl;}
template <typename T> void print(vector<vector<T>> &v) {for(auto elem: v) print(elem); cout << endl;}

void makeG(vector<vector<int>> &g, vector<int> &u, vector<int> &v) {
	for(int i=0; i<u.size(); i++) {
		g[u[i]].push_back(v[i]);
		g[v[i]].push_back(u[i]);
	}
}
int decideSubtaskLabel(int n, int k, vector<vector<int>> &g, vector<int> &u, vector<int> &v) {
	int subtask = 0, cnt = 0;
	bool subtask2 = true;
	for(int i=0; i<n; i++) {
		if (g[i].size()>2) cnt++;
		if (!(u[i]==i+1 && v[i]==i/2 || u[i]==i/2 && v[i]==i+1)) subtask2= false;
	}
	if (cnt==0) return 1;
	if (subtask2) return 2;
	if (cnt==1) return 3;
}
void subtask1Label(int n, vector<vector<int>> &g, vector<int> &labels) {
	int node = 0;
	for(int i=0; i<n; i++)
		if(g[i].size()==1) node=i;

	int cnt = 0;
	while(labels[node]==-1) {
		labels[node] = cnt++; 
		for(int elem: g[node])
			if(labels[elem]==-1) node = elem;
	}
}
std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	vector<vector<int>> g(n);
	makeG(g,u,v);
	// print(g);
	int subtask = decideSubtaskLabel(n,k,g,u,v);
	vector<int> labels(n,-1);
	switch(subtask) {
		case 1: subtask1Label(n,g,labels); return labels;
		// case 2: 
		// case 3:
	}
}
int decideSubtaskFind(int s, int t, vector<int> &c) {
	return 1;
}
int subtask1Find(int s, int t, vector<int> &c) {
	if (c.size()==1) return c[0];
	else return t<s? c[0]:c[1];
}
int find_next_station(int s, int t, std::vector<int> c) {
	int subtask = decideSubtaskFind(s,t,c);
	switch(subtask) {
		case 1: return subtask1Find(s,t,c);
	}
	return c[0];
}

Compilation message (stderr)

stations.cpp: In function 'void makeG(std::vector<std::vector<int> >&, std::vector<int>&, std::vector<int>&)':
stations.cpp:10:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for(int i=0; i<u.size(); i++) {
      |               ~^~~~~~~~~
stations.cpp: In function 'int decideSubtaskLabel(int, int, std::vector<std::vector<int> >&, std::vector<int>&, std::vector<int>&)':
stations.cpp:20:19: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   20 |   if (!(u[i]==i+1 && v[i]==i/2 || u[i]==i/2 && v[i]==i+1)) subtask2= false;
stations.cpp:16:6: warning: unused variable 'subtask' [-Wunused-variable]
   16 |  int subtask = 0, cnt = 0;
      |      ^~~~~~~
stations.cpp:25:1: warning: control reaches end of non-void function [-Wreturn-type]
   25 | }
      | ^
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:39:25: warning: control reaches end of non-void function [-Wreturn-type]
   39 |  vector<vector<int>> g(n);
      |                         ^

• Subtask 1: 5 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61