Submission #131161

#	Time	Username	Problem	Language	Result	Execution time	Memory
131161		junodeveloper	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

string guess_sequence(int N) {
	int r;
	string t = "ABXY", p, s = "";
	r = press("AB");
	if(r == 0) {
		r = press("X");
		if(r == 0) s = "Y";
		else s = "X";
	} else {
		r = press("A");
		if(r == 0) s = "B";
		else s = "A";
	}
	if(N == 1) return s;
	for(int i=0; i<4; i++) {
		if(t[i] == s[0]) {
			t = t.substr(0,i) + (i+1<4 ? t.substr(i+1) : "");
			break;
		}
	}
	for(int i=1; i+1<N; i++) {
		p = "";
		for(int j=0; j<3; j++) {
			p += s + t[0] + t[j];
		}
		p += s + t[1];
		r = press(p);
		if(r == i) {
			s += t[2];
		} else if(r == i+1) {
			s += t[1];
		} else s += t[0];
	}
	p = s + t[0];
	if(r == N) s += t[0];
	else {
		p = s + t[1];
		if(r == N) s += t[1];
		else s += t[2];
	}
	return s;
}

Compilation message (stderr)

combo.cpp:1:1: error: 'string' does not name a type
    1 | string guess_sequence(int N) {
      | ^~~~~~