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#include "aoc.h"
#include <algorithm>
#include <vector>
namespace aoc2021 {
int get_number(const char* p) {
int d{0};
while (*p >= '0' && *p <= '9') {
d = d * 10 + *p - '0';
p++;
}
return d;
}
int increase_1(const std::vector<int>& is) {
int total{0};
int last{0};
std::for_each(is.begin(), is.end(), [&total, &last](int d) {
total += (last != 0 && d > last) ? 1 : 0;
last = d;
return true;
});
return total;
}
int increase_3(const std::vector<int>& is) {
int total{0};
auto sum3 = [](const int* is) { return *is + *(is + 1) + *(is + 2); };
const int* p1 = is.data();
const int* p2 = p1 + is.size() - 3;
while (p1 < p2) {
if (sum3(p1 + 1) > sum3(p1)) {
total += 1;
}
p1++;
}
return total;
}
std::pair<int, int> day1(line_view file) {
std::vector<int> is;
per_line(file, [&is](line_view lv) {
is.emplace_back(get_number(lv.line));
return true;
});
return {increase_1(is), increase_3(is)};
}
} // namespace aoc2021
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