Submission #99114

#	Time	Username	Problem	Language	Result	Execution time	Memory
99114		JustasLe	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;

string guess_sequence(int N) {
	srand(time(null));
	for (int i = 0; i < 10000; i++) {

	}
	set<char> X = {'A', 'B', 'X', 'Y'};
	string s = "";
	for (auto it = X.begin(); it != X.end(); it++) {
		int x = press(s + *it);
		if (x != 0) {
			s += *it;
			X.erase(*it);
			break; 
		}
	}
	if (s == "") {
		return s;
	}
	string Y = "";
	for (auto it = X.begin(); it != X.end(); it++) {
		Y += *it;
	}
	int prev = 1;
	bool ok = true;
	while (ok) {
		ok = false;
		int x;
		set<int> W;
		while ((int) W.size() != 3) {
			int rn = ((rand() + rand())% 3);
			if (!W.count(rn)) {
				x = press(s + Y[rn]);
				if (x > prev) {
					s += Y[rn];
					prev++;
					break;
				}
				W.insert(rn);	
			}
		}
		if ((int) s.size() == N || x == prev) {
			break;
		}
	}
	return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:7:13: error: 'null' was not declared in this scope
    7 |  srand(time(null));
      |             ^~~~