Submission #1062579

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062579		nightfal	Stations (IOI20_stations)	C++17	29 / 100	1199 ms	2097152 KiB

stations

#include <vector>
#include <iostream>
#include <cmath>
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 labelSubDecision(int n, int k, vector<vector<int>> &g, vector<int> &u, vector<int> &v) {
	if (k==pow(10,9)) return 4;
	int cnt = 0;
	for(int i=0; i<n; i++)
		if (g[i].size()>2) cnt++;
	if (cnt==0) return 1;

	bool subtask2 = true;
	for(int i=0; i<u.size(); i++)
		if (!(u[i]==i+1 && v[i]==i/2 || u[i]==i/2 && v[i]==i+1)) subtask2= false;
	if (subtask2) return 2;

	if (cnt==1) return 3;
}
void labelLine(int cnt, int node, vector<vector<int>> &g, vector<int> &labels) {
	while(labels[node]==-1) {
		labels[node] = cnt++;
		for(int elem: g[node])
			if (labels[elem]==-1) node = elem;
	}
	return;
}
void labelSub1(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;

	labelLine(0,node,g,labels);
	return;
}
void labelSub2(int n, vector<int> &labels) {
	for(int i=0; i<n; i++)
		labels[i] = i+1;
	return;
}
void labelSub3(int n, vector<vector<int>> &g, vector<int> &labels) {
	int root = 0;
	for(int i=0; i<n; i++)
		if(g[i].size() > 2) {root = i; break;}
	labels[root] = 1'000;
	for(int i=0; i<g[root].size(); i++)
		labelLine((i+1)*1'000+1,g[root][i],g,labels);
}
void dfs(int node, int base, int offset, vector<vector<int>> &g, vector<int> &labels) {
	labels[node] = base + offset;
	for(int i=0; i<g[node].size(); i++)
		dfs(g[node][i],labels[node],offset/10*(i+1),g,labels);
	return;
}
void labelSub4(int n, vector<vector<int>> &g, vector<int> &labels) {
	dfs(0,0,pow(10,7),g,labels);
	return;
}

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 = labelSubDecision(n,k,g,u,v);
	vector<int> labels(n,-1);
	switch(subtask) {
		case 1: labelSub1(n,g,labels); return labels;
		case 2: labelSub2(n,labels); return labels;
		case 3: labelSub3(n,g,labels); return labels;
		case 4: labelSub4(n,g,labels); return labels;
	}
}
int findSubDecision(int s, int t, vector<int> &c) {
	if (s >= pow(10,7)) return 4;
	if (s >= 1'000 && t >= 1'000) return 3;
	for(int i=0; i<c.size(); i++)
		if (c[i] < s-1 || c[i] > s+1) return 2;
	return 1;
}
int findSub1(int s, int t, vector<int> &c) {
	if (c.size()==1) return c[0];
	else return t<s? c[0]:c[1];
}
bool ancestor(int a, int b) {
	if (a==0) return true;
	while(b!=0) { if(a==b) return true; else b >>= 1; }
	return false;
}
int findSub2(int s, int t, vector<int> &c) {
	for(int i=c.size()-1; i>=0; i--)
		if(ancestor(c[i],t)) return c[i];
	return c[0];
}
int findSub3(int s, int t, vector<int> &c) {
	if (s==1'000) {
		for(int elem: c)
			if(t/1000==elem/1000) return elem;
	}
	else if (s/1000 == t/1000) {
		if(s < t) {
			for(int elem: c)
				if(elem > s) return elem;
		}
		else {
			for(int elem: c)
				if(elem < s) return elem;
		}
	}
	else {
			for(int elem: c)
				if(elem < s) return elem;
	}
}
bool ancestor4(int a, int b) {
	int divisor = 1;
	for(int i=0; i<=7; i++) {
		if (b - b % divisor == a) return true;
		divisor *= 10;
	}
	return false;
}
int findSub4(int s, int t, vector<int> &c) {
	for(int i=c.size()-1; i>=0; i--)
		if(ancestor4(c[i],t)) return c[i];
	return c[0];
}
int find_next_station(int s, int t, std::vector<int> c) {
	int subtask = findSubDecision(s,t,c);
	switch(subtask) {
		case 1: return findSub1(s,t,c);
		case 2: return findSub2(s,t,c);
		case 3: return findSub3(s,t,c);
		case 4: return findSub4(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:11:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |  for(int i=0; i<u.size(); i++) {
      |               ~^~~~~~~~~
stations.cpp: In function 'int labelSubDecision(int, int, std::vector<std::vector<int> >&, std::vector<int>&, std::vector<int>&)':
stations.cpp:24:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  for(int i=0; i<u.size(); i++)
      |               ~^~~~~~~~~
stations.cpp:25:19: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   25 |   if (!(u[i]==i+1 && v[i]==i/2 || u[i]==i/2 && v[i]==i+1)) subtask2= false;
stations.cpp: In function 'void labelSub3(int, std::vector<std::vector<int> >&, std::vector<int>&)':
stations.cpp:56:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |  for(int i=0; i<g[root].size(); i++)
      |               ~^~~~~~~~~~~~~~~
stations.cpp: In function 'void dfs(int, int, int, std::vector<std::vector<int> >&, std::vector<int>&)':
stations.cpp:61:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |  for(int i=0; i<g[node].size(); i++)
      |               ~^~~~~~~~~~~~~~~
stations.cpp: In function 'int findSubDecision(int, int, std::vector<int>&)':
stations.cpp:86:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |  for(int i=0; i<c.size(); i++)
      |               ~^~~~~~~~~
stations.cpp: In function 'int labelSubDecision(int, int, std::vector<std::vector<int> >&, std::vector<int>&, std::vector<int>&)':
stations.cpp:29:1: warning: control reaches end of non-void function [-Wreturn-type]
   29 | }
      | ^
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:71:25: warning: control reaches end of non-void function [-Wreturn-type]
   71 |  vector<vector<int>> g(n);
      |                         ^
stations.cpp: In function 'int findSub3(int, int, std::vector<int>&)':
stations.cpp:123:1: warning: control reaches end of non-void function [-Wreturn-type]
  123 | }
      | ^

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