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#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <map>
#include "../utils.h"
std::map<std::string, long> apply (std::map<std::string, long> pairs,
std::map<std::string, char> rules, std::map<char, long> &count)
{
std::map<std::string, long> next = pairs;
for (auto &pair : pairs) {
char c = rules[pair.first];
count[c] += pair.second;
std::string l;
l.push_back(pair.first[0]);
l.push_back(c);
std::string r;
r.push_back(c);
r.push_back(pair.first[1]);
next[pair.first] -= pair.second;
next[l] += pair.second;
next[r] += pair.second;
}
return next;
}
void to_pairs (std::string init, std::map<std::string, long> &pairs) {
for (std::size_t i=0; i<init.size()-1; i++) {
std::string seg = init.substr(i, 2);
pairs[seg] ++;
}
}
long tally (std::map<char, long> map) {
std::vector<long> f;
for (auto p : map) {
f.push_back(p.second);
std::cout << p.first << " " << p.second << std::endl;
}
std::sort(f.begin(), f.end());
return f[f.size()-1] - f[0];
}
int main (int argc, char *argv[]) {
std::string raw;
std::getline(std::ifstream(argv[1]), raw, '\0');
std::vector<std::string> parts, strrules;
split(parts, raw, "\n\n");
split(strrules, parts[1], "\n");
std::string polymer = parts[0];
std::cout << "starting polymer: " << polymer << std::endl;
std::map<std::string, long> pairs;
std::map<std::string, char> rules;
for (auto strrule : strrules) {
if (strrule.size() == 0) continue;
std::vector<std::string> rl;
split(rl, strrule, " -> ");
rules[rl[0]] = rl[1][0];
pairs[rl[0]] = 0;
}
to_pairs(polymer, pairs);
std::map<char, long> count;
for (auto pair : pairs) {
count[pair.first[0]] = 0;
count[pair.first[1]] = 0;
}
for (char c : polymer) {
count[c] ++;
}
long iter = 10;
if (argc > 2) iter = atoi(argv[2]);
for (long i=0; i<iter; i++) {
pairs = apply(pairs, rules, count);
}
long res = tally(count);
std::cout << "most common - least common: " << res << std::endl;
return 0;
}
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