advent-of-code/2023/1/main.cpp

#include <bits/stdc++.h>
using namespace std;

const string NUMBERS[] = {
	"one",
	"two",
	"three",
	"four",
	"five",
	"six",
	"seven",
	"eight",
	"nine",
};

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int ret = 0;

	string line;
	while (getline(cin, line) && !line.empty()) {
		int pi = INT_MAX, pl = -1, vi = 0, vl = 0;
		for (int i = 0; i < line.size(); i++) {
			unsigned char c = line[i] - '0';
			if (c <= 9) {
				if (vi == 0) {
					pi = i;
					vi = c;
				}
				pl = i;
				vl = c;
			}
		}
		for (int n = 1; n <= 9; n++) {
			const auto strn = NUMBERS[n - 1];
			int i = 0;
			int posi = line.find(strn);
			if (posi == string::npos)
				continue;
			int posl = line.rfind(strn);
			if (posi < pi) {
				pi = posi;
				vi = n;
			}
			if (posl > pl) {
				pl = posl;
				vl = n;
			}
		}
		ret += vi * 10 + vl;
	}

	cout << ret << '\n';
}