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#include "aoc.h"
#include <map>
namespace aoc2021 {
static void get_number(const char** pp, int* d) {
const char* p = *pp;
*d = 0;
while (*p >= '0' && *p <= '9') {
*d = *d * 10 + *p - '0';
p++;
}
*pp = p;
}
int crab_move(int x, int y) {
int b = std::abs(x - y);
return b * (b + 1) / 2;
}
std::pair<int, int> fuel(int a, const std::map<int, int>& is) {
int t0{0};
int t1{0};
for (auto& kv : is) {
if (kv.first != a) {
t0 += std::abs(a - kv.first) * kv.second;
t1 += crab_move(a, kv.first) * kv.second;
}
}
return {t0, t1};
}
std::pair<int, int> day7(line_view file) {
std::map<int, int> is;
const char* p1 = file.line;
const char* p2 = p1 + file.length;
int mi{INT32_MAX};
int mx{INT32_MIN};
while (p1 < p2) {
if (*p1 >= '0' && *p1 <= '9') {
int d{0};
get_number(&p1, &d);
mi = std::min(mi, d);
mx = std::max(mx, d);
is[d] += 1;
}
p1++;
}
int m1{INT32_MAX};
int m2{INT32_MAX};
for (int i = mi; i <= mx; i++) {
auto p = fuel(i, is);
// printf("%d -> (%d, %d)\n", i, p.first, p.second);
if (p.first < m1) {
m1 = p.first;
}
if (p.second < m2) {
m2 = p.second;
}
}
return {m1, m2};
}
} // namespace aoc2021
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