Submission #1077933

#	Time	Username	Problem	Language	Result	Execution time	Memory
1077933		TB_	Toy Train (IOI17_train)	C++17	Compilation error	0 ms	0 KiB

train

#include <bits/stdc++.h>

using namespace std;
#define ll long long 
#define fo(i, n) for(ll i = 0; i<(n); i++)
#define F first 
#define S second 
#define pb push_back 
#define deb(x) cout << #x << " = " << (x) << endl
#define deb2(x, y) cout << #x << " = " << (x)  << ", " << #y << " = " << (y) << endl

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef pair<ll, ll> pl;
typedef vector<pl> vpl;

ll n;
vl topo;
int seen[6000];
vvl adj(6000);
vvl adjR(6000);

int toposort(int u){
    if(seen[u]) return;
    seen[u] = 1;
    for(auto &v : adj[u]){
        toposort(v);
    }
    topo.pb(u);
}

int c = 0;

int dfs(int u){
    if(seen[u]) return 0;
    seen[u] = c;
    ll ans = 1;
    for(auto &v : adj[u]){
        ans+=dfs(v);
    }
    return ans;
}

vector<int> res;

void dfs2(int u){
    if(!res[u]) return;
    res[u] = 0;
    for(auto &v : adjR[u]){
        dfs2(v);
    }
}


std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
    n = a.size();
    ll m = u.size();

    vl selfEdge(n+1, 0);
    fo(i, m){
        if(u[i] == v[i]) selfEdge[u[i]] = 1;
        else{
            if(!r[i])adj[u[i]].pb(v[i]);
            adjR[v[i]].pb(u[i]);
        }
    }

    memset(seen, 0, sizeof(seen));
	fo(i, n){
        if(seen[i]) continue;
        toposort(i);
    }
    reverse(all(topo));
    memset(seen, 0, sizeof(seen));
    vl good;
    fo(i, n){
        if(seen[i]) continue;
        c++;
        ll siz = dfs(i);
        if(siz>1 || selfEdge[i]) good.pb(i);
    }
    res.assign(n, 1);
    fo(i, good.size()){
        dfs2(good[i]);
    }

	return res;
}

Compilation message (stderr)

train.cpp: In function 'int toposort(int)':
train.cpp:27:17: error: return-statement with no value, in function returning 'int' [-fpermissive]
   27 |     if(seen[u]) return;
      |                 ^~~~~~
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:5:33: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    5 | #define fo(i, n) for(ll i = 0; i<(n); i++)
      |                                 ^
train.cpp:86:5: note: in expansion of macro 'fo'
   86 |     fo(i, good.size()){
      |     ^~
train.cpp: In function 'int toposort(int)':
train.cpp:32:12: warning: control reaches end of non-void function [-Wreturn-type]
   32 |     topo.pb(u);
      |     ~~~~~~~^~~