Kyselyt

input/code.cpp: In function 'int main()':
input/code.cpp:45:28: error: too few arguments to function 'std::string toString(int, int)'
    result += toString(index);
                            ^
input/code.cpp:13:8: note: declared here
 string toString(int val, int a) {
        ^

#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>
//#include <sstream>

using namespace std;

unsigned getDigits(unsigned int value) {
    return value > 0 ? (int) log10 ((double) value) + 1 : 1;
}

string toString(int val, int a) {
	string res;
	for (int i = 0; i < a; i++) {
		res += (char)val % 10;
		val /= 10;
	}
	reverse(res.begin(), res.end());
	return res;
}

int main() {
	int amount;
	cin >> amount;
	int *a = new int[amount];
	int cur;
	int index;
	int size;
	int digits;
	string result;
	for (int i = 0; i < amount; i++) {
		cin >> a[i];
	}
	for (int i = 0; i < amount; i++) {
		cur = a[i];
		index = 1;
		size = 0;
		digits = 0;
		//stringstream ss;

		for (; size <= cur; index++) {
			digits = getDigits(index);
			//ss << index;
			result += toString(index);
			size += digits;
		}

		cout << result.at(cur - 1) << '\n';
	}
	//while (1);
	return 0;
}