Submission #1148871

#	Time	Username	Problem	Language	Result	Execution time	Memory
1148871		andrejikus	Combo (IOI18_combo)	C++20	Compilation error	0 ms	0 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) { cerr << to_string(h); if(sizeof...(t)) cerr << ", "; DBG(t...); }
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)

const int N = 2e5 + 3;
string ELEM[4] = {"A", "B", "X", "Y"};

string guess_sequence(int n) {

    string s = "";
    string p = ELEM[0] + ELEM[1];
    if (press(p) > 0) {
        string c = ELEM[0];
        if (press(c))
            s += ELEM[0];
        else
            s += ELEM[1];
    } else {
        string c = ELEM[2];
        if (press(c))
            s += ELEM[2];
        else
            s += ELEM[3];
    }
    /// 3 qry

    for (int i = 2; i <= n; i++) {
        vector<string> vec;
        for (int d = 0; d < 4; d++)
            if (s[0] != char(ELEM[d]))
                vec.push_back(ELEM[d]);
        string p = s + vec[0] + s + vec[1];
        if (press(p) == i) {
            string c = s + vec[0];
            if (press(c) == i)
                s += vec[0];
            else
                s += vec[1];
        } else {
            s += vec[2];
        }
    }

    return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:34:25: error: invalid cast from type 'std::string' {aka 'std::__cxx11::basic_string<char>'} to type 'char'
   34 |             if (s[0] != char(ELEM[d]))
      |                         ^~~~~~~~~~~~~