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#include <fstream>
#include <iostream>
using namespace std;
string
read_file(const string& filename)
{
fstream input{ filename };
string line;
getline(input, line);
return line;
}
void
part1(string_view line)
{
size_t len = 0;
for ( size_t i = 0; i != line.length(); ) {
if ( size_t lhs = 0, rhs = 0; sscanf(&line[i], "(%zux%zu)", &lhs, &rhs) == 2 ) {
i = line.find(')', i) + 1 + lhs;
len += lhs * rhs;
}
else {
++i;
++len;
}
}
cout << len << endl;
}
void
part2(string_view line)
{
function<size_t(string_view)> part2_rec = [&](string_view line) {
size_t len = 0;
for ( size_t i = 0; i != line.length(); ) {
if ( size_t lhs = 0, rhs = 0; sscanf(&line[i], "(%zux%zu)", &lhs, &rhs) == 2 ) {
i = line.find(')', i) + 1;
len += part2_rec({ &line[i], lhs }) * rhs;
i += lhs;
}
else {
++i;
++len;
}
}
return len;
};
cout << part2_rec(line) << endl;
}
int
main()
{
auto line = read_file("data/day09.txt");
// part1("ADVENT");
// part1("A(1x5)BC");
// part1("(3x3)XYZ");
// part1("A(2x2)BCD(2x2)EFG");
// part1("(6x1)(1x3)A");
// part1("X(8x2)(3x3)ABCY");
part1(line);
part2(line);
}
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