Submission #778480

#	Time	Username	Problem	Language	Result	Execution time	Memory
778480		I_Love_EliskaM_	Toy Train (IOI17_train)	C++14	5 / 100	940 ms	1520 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for(int i=0;i<n;++i)
#define pb push_back
#define ll long long

vector<int> p1(vector<int>a,vector<int>r,vector<int>u,vector<int>v) {
	int n=a.size(), m=u.size();
	vector<int> s(n);
	vector<int> f(n);
	vector<int> ans(n);
	forn(i,m) if (u[i]==v[i]) s[u[i]]=1;
	forn(i,m) if (u[i]!=v[i]) f[u[i]]=1;
	int now=0;
	for (int i=n-1; i>=0; --i) {
		if (s[i]) {
			if (now) {
				if (!a[i]) {
					if (!r[i]) now=0;
				} else {
					if (f[i]) now=1;
					else now = r[i];
				}
			} else {
				if (a[i]) {
					if (r[i]) now=1;
				} else {
					if (f[i]) now=0;
					else now = r[i];
				}
			}
		}
		ans[i]=now;
	}
	return ans;
}

const int N=5555;
vector<int> adj[N];
int vis[N];
int ok[N];
int dfs(int u, int s) {
	if (vis[u] && u==s) return 1;
	if (vis[u]) return 0;
	vis[u]=1;
	int z=0;
	for(auto&v:adj[u]) z|=dfs(v,s);
	return z;
}
int dfs2(int u) {
	if (ok[u]) return 1;
	if (vis[u]) return 0;
	vis[u]=1;
	int z=0;
	for(auto&v:adj[u]) z|=dfs2(v);
	return z;
}
vector<int> p3(vector<int>a,vector<int>r,vector<int>u,vector<int>v) {
	int n=a.size(), m=u.size();
	vector<int> ans(n);
	vector<int> ok(n);
	forn(i,m) adj[u[i]].pb(v[i]);
	forn(i,n) if (r[i]) {
		forn(j,n) vis[j]=0;
		int q=dfs(i,i);
		ok[i]=q;
	}
	forn(i,n) {
		forn(j,n) vis[j]=0;
		int q=dfs2(i);
		ans[i]=q;
	}
	return ans;
}

vector<int> p4(vector<int>a,vector<int>r,vector<int>u,vector<int>v) {
	int n=a.size(), m=u.size();
	vector<int> s(n);
	vector<int> ans(n);
	forn(i,m) if (u[i]==v[i]) s[i]=1;
	int now;
	for (int i=n-1; i>=0; --i) {
		if (s[i]) now=a[i];
		ans[i]=now;
	}
	return ans;
}

vector<int> who_wins(vector<int>a,vector<int>r,vector<int>u,vector<int>v) {

	int n=a.size(), m=u.size();
	int z=1;
	forn(i,m) z&=(u[i]==v[i]) || (v[i]==(u[i]+1));
	if (z) {
		return p1(a,r,u,v);
	}
	z=1;
	forn(i,n) z&=a[i];
	if (z) return p3(a,r,u,v);
	forn(i,n) z|=a[i];
	if (!z) return p4(a,r,u,v);

}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:104:1: warning: control reaches end of non-void function [-Wreturn-type]
  104 | }
      | ^
train.cpp: In function 'std::vector<int> p4(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:85:9: warning: 'now' may be used uninitialized in this function [-Wmaybe-uninitialized]
   85 |   ans[i]=now;

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