Submission #1128463

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128463		algoproclub	Stations (IOI20_stations)	C++20	Compilation error	0 ms	0 KiB

stations

#include "stations.h"
#include <algorithm>
#include <vector>

using namespace std;

vector<vector<int>> g;
vector<int> intime, outtime, depth;
int time;

void dfs(int v) {
    intime[v] = time++;
    for (int x : g[v])
        if (intime[x] == -1) {
            depth[x] = depth[v] + 1;
            dfs(x);
        }
    outtime[v] = time++;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	g.assign(n, {});
	intime.assign(n, -1);
	outtime.assign(n, -1);
	depth.assign(n, 0);
	for (int i = 0; i < n - 1; i++) {
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
	}
	time = 0;
	dfs(0);
	vector<int> labels(n);
	for (int i = 0; i < n; i++) {
		labels[i] = depth[i] % 2 == 0 ? intime[i] / 2 : outtime[i] / 2;
	}
	return labels;
}

int find_next_station(int s, int t, vector<int> c) {
    // sort(c.begin(), c.end()); they are already sorted
    if (s < c[0]) {
        // s: intime, c[i]: outtime, c.back(): parent of s
        // subtree of s: s < t <= c[c.size() - 2],
        // except if s==0 (root), but the below code is correct for it, too
        if (t < s || c.size() == 1 || t > c[c.size() - 2])
            return c.back();
        return *lower_bound(c.begin(), c.end(), t);
    } else {
        // s: outtime, c[i]: intime, c[0]: parent of s
        // subtree of s: c[1] <= t < s
        if (t > s || c.size() == 1 || t < c[1])
            return c[0];
        return *(upper_bound(c.begin(), c.end(), t) - 1);
    }

}

Compilation message (stderr)

stations.cpp:9:5: error: 'int time' redeclared as different kind of entity
    9 | int time;
      |     ^~~~
In file included from /usr/include/pthread.h:23,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/gthr-default.h:35,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/gthr.h:148,
                 from /usr/include/c++/11/ext/atomicity.h:35,
                 from /usr/include/c++/11/bits/ios_base.h:39,
                 from /usr/include/c++/11/streambuf:41,
                 from /usr/include/c++/11/bits/streambuf_iterator.h:35,
                 from /usr/include/c++/11/iterator:66,
                 from /usr/include/c++/11/bits/ranges_algobase.h:36,
                 from /usr/include/c++/11/bits/ranges_algo.h:35,
                 from /usr/include/c++/11/algorithm:64,
                 from stations.cpp:2:
/usr/include/time.h:76:15: note: previous declaration 'time_t time(time_t*)'
   76 | extern time_t time (time_t *__timer) __THROW;
      |               ^~~~
stations.cpp: In function 'void dfs(int)':
stations.cpp:12:17: warning: ISO C++ forbids incrementing a pointer of type 'time_t (*)(time_t*) noexcept' {aka 'long int (*)(long int*) noexcept'} [-Wpointer-arith]
   12 |     intime[v] = time++;
      |                 ^~~~
stations.cpp:12:17: error: lvalue required as increment operand
stations.cpp:18:18: warning: ISO C++ forbids incrementing a pointer of type 'time_t (*)(time_t*) noexcept' {aka 'long int (*)(long int*) noexcept'} [-Wpointer-arith]
   18 |     outtime[v] = time++;
      |                  ^~~~
stations.cpp:18:18: error: lvalue required as increment operand
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:30:14: error: assignment of function 'time_t time(time_t*)'
   30 |         time = 0;
      |         ~~~~~^~~