Submission #70160

#	Time	Username	Problem	Language	Result	Execution time	Memory
70160		bnahmad15	Toy Train (IOI17_train)	C++17	0 / 100	15 ms	1856 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;

const int N = 5001;
int n,is[N],vis[N],own[N],to[N],self[N],flag1 = 1,flag2 = 1,low[N],tim[N],cnt = 0,can[N],comp[N],cc = 0,have[N],cycle[N];
vector <int> g[N],S,g2[N];

int dfs(int u){
	vis[u] = 1;
	S.push_back(u);
	int ret;
	if(own[u] == 0){
		ret = 1;
		for(int i = 0;i<g[u].size();i++){
			int v = g[u][i];
			if(vis[v] == 1){
				int flag = 0;
				for(int j = S.size()-1;j>=0;j--){
					if(is[S[j]] == 1){
						flag = 1;
						break;
					}
					if(S[j] == v)
						break;
				}
				ret = min(ret,flag);
			}else{
				ret = min(ret,dfs(v));
			}
		}
	}else{
		ret = 0;
		for(int i = 0;i<g[u].size();i++){
			int v = g[u][i];
			if(vis[v] == 1){
				int flag = 0;
				for(int j = S.size()-1;j>=0;j--){
					if(is[S[j]] == 1){
						flag = 1;
						break;
					}
					if(S[j] == v)
						break;
				}
				ret = max(ret,flag);
			}else{
				ret = max(ret,dfs(v));
			}
		}
	}
	vis[u] = 0;
	S.pop_back();
	return ret;
}

void DFS(int u){
	low[u] = tim[u] = ++cnt;
	vis[u] = 1;
	S.push_back(u);
	for(int i = 0;i<g[u].size();i++){
		int v = g[u][i];
		if(tim[v] == -1)
			DFS(v);
		if(vis[v])
			low[u] = min(low[u],low[v]);
	}
	if(low[u] == tim[u]){
		cc++;
		int tmpp = 0;
		while(1){
			int v = S.back(); S.pop_back(); vis[v] = 0;
			comp[v] = cc;
			tmpp++;
			if(v == u) break;
		}
		if(tmpp > 1)
			cycle[cc] = 1;
	}
}
int calc(int u){
	if(can[u] != -1)
		return can[u];
	can[u] = 0;
	if(cycle[u] == 1 && have[u] == 1)
		return can[u] = 1;
	for(int i = 0;i<g2[u].size();i++){
		can[u] = max(can[u],calc(g2[u][i]));
	}
	return can[u];
}
std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {

	std::vector<int> res;
	n = a.size();
	for(int i = 0;i<n;i++){
		is[i] = self[i] = to[i] = 0,vis[i] = 0;
		have[i] = cycle[i] =0;
	}
	for(int i = 0;i<u.size();i++){
		g[u[i]].push_back(v[i]);
		if(u[i] == v[i])
			self[u[i]] = 1;
		if(u[i] + 1 == v[i])
			to[u[i]] = 1;
	}
	for(int i = 0;i<n;i++)
		is[i] = r[i];
	for(int i = 0;i<n;i++){
		own[i] = a[i];
		if(a[i] != 1)
			flag1 = 0;
		if(a[i] != 0)
			flag2 = 0;
	}
	if(n <= 15){
		return res;
		int cnt = 0;
		for(int i = 0;i<n;i++){
			for(int j = 0;j<n;j++){
				vis[j] = 0;
			}
			cnt++;
			res.push_back(dfs(i));
		}
	}else if(flag1 == 1){
		for(int i = 0;i<n;i++){
			if(tim[i] == -1)
				DFS(i);
		}
		for(int i = 0;i<n;++i){
			for(int j = 0;j<g[i].size();j++){
				if(comp[i] != comp[g[i][j]])
					g2[comp[i]].push_back(g[i][j]);
			}
			if(is[i])
				have[comp[i]] = 1;
			can[i] = -1;
		}
		for(int i = 0;i<n;i++)
			res.push_back(calc(i));
	}else{
		return res;
		if(is[n-1] && self[n-1])
			res.push_back(1);
		else
			res.push_back(0);
		for(int i = n-2;i>=0;i--){
			if(own[i] == 0){
				int ret = 1;
				ret = min(ret,((!is[i] && self[i]) ? 0 : 1));
				ret = min(ret,((to[i]) ? res.back() : 1));
				res.push_back(ret);
			}else{
				int ret = 0;
				ret = max(ret,((is[i] && self[i]) ? 1 : 0));
				ret = max(ret,((to[i]) ? res.back() : 0));
				res.push_back(ret);				
			}
		}
		reverse(res.begin(),res.end());
	}
	return res;
}

Compilation message (stderr)

train.cpp: In function 'int dfs(int)':
train.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0;i<g[u].size();i++){
                 ~^~~~~~~~~~~~
train.cpp:34:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0;i<g[u].size();i++){
                 ~^~~~~~~~~~~~
train.cpp: In function 'void DFS(int)':
train.cpp:61:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i<g[u].size();i++){
                ~^~~~~~~~~~~~
train.cpp: In function 'int calc(int)':
train.cpp:87:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i<g2[u].size();i++){
                ~^~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:100:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i<u.size();i++){
                ~^~~~~~~~~
train.cpp:132:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j = 0;j<g[i].size();j++){
                  ~^~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51