RosettaCodeData/Task/Esthetic-numbers/C++/esthetic-numbers.cpp

121 lines
3.3 KiB
C++

#include <functional>
#include <iostream>
#include <sstream>
#include <vector>
std::string to(int n, int b) {
static auto BASE = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
std::stringstream ss;
while (n > 0) {
auto rem = n % b;
n = n / b;
ss << BASE[rem];
}
auto fwd = ss.str();
return std::string(fwd.rbegin(), fwd.rend());
}
uint64_t uabs(uint64_t a, uint64_t b) {
if (a < b) {
return b - a;
}
return a - b;
}
bool isEsthetic(uint64_t n, uint64_t b) {
if (n == 0) {
return false;
}
auto i = n % b;
n /= b;
while (n > 0) {
auto j = n % b;
if (uabs(i, j) != 1) {
return false;
}
n /= b;
i = j;
}
return true;
}
void listEsths(uint64_t n, uint64_t n2, uint64_t m, uint64_t m2, int perLine, bool all) {
std::vector<uint64_t> esths;
const auto dfs = [&esths](uint64_t n, uint64_t m, uint64_t i) {
auto dfs_impl = [&esths](uint64_t n, uint64_t m, uint64_t i, auto &dfs_ref) {
if (i >= n && i <= m) {
esths.push_back(i);
}
if (i == 0 || i > m) {
return;
}
auto d = i % 10;
auto i1 = i * 10 + d - 1;
auto i2 = i1 + 2;
if (d == 0) {
dfs_ref(n, m, i2, dfs_ref);
} else if (d == 9) {
dfs_ref(n, m, i1, dfs_ref);
} else {
dfs_ref(n, m, i1, dfs_ref);
dfs_ref(n, m, i2, dfs_ref);
}
};
dfs_impl(n, m, i, dfs_impl);
};
for (int i = 0; i < 10; i++) {
dfs(n2, m2, i);
}
auto le = esths.size();
printf("Base 10: %d esthetic numbers between %llu and %llu:\n", le, n, m);
if (all) {
for (size_t c = 0; c < esths.size(); c++) {
auto esth = esths[c];
printf("%llu ", esth);
if ((c + 1) % perLine == 0) {
printf("\n");
}
}
printf("\n");
} else {
for (int c = 0; c < perLine; c++) {
auto esth = esths[c];
printf("%llu ", esth);
}
printf("\n............\n");
for (size_t i = le - perLine; i < le; i++) {
auto esth = esths[i];
printf("%llu ", esth);
}
printf("\n");
}
printf("\n");
}
int main() {
for (int b = 2; b <= 16; b++) {
printf("Base %d: %dth to %dth esthetic numbers:\n", b, 4 * b, 6 * b);
for (int n = 1, c = 0; c < 6 * b; n++) {
if (isEsthetic(n, b)) {
c++;
if (c >= 4 * b) {
std::cout << to(n, b) << ' ';
}
}
}
printf("\n");
}
printf("\n");
// the following all use the obvious range limitations for the numbers in question
listEsths(1000, 1010, 9999, 9898, 16, true);
listEsths((uint64_t)1e8, 101'010'101, 13 * (uint64_t)1e7, 123'456'789, 9, true);
listEsths((uint64_t)1e11, 101'010'101'010, 13 * (uint64_t)1e10, 123'456'789'898, 7, false);
listEsths((uint64_t)1e14, 101'010'101'010'101, 13 * (uint64_t)1e13, 123'456'789'898'989, 5, false);
listEsths((uint64_t)1e17, 101'010'101'010'101'010, 13 * (uint64_t)1e16, 123'456'789'898'989'898, 4, false);
return 0;
}