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#pragma once
#include <functional>
#include <map>
#include "common.h"
namespace aoc2015 {
struct result {
enum {
c_unknown,
c_value,
} type;
uint16_t value;
result op_and(result other) {
if (type == c_value && other.type == c_value) {
return result{c_value, uint16_t(value & other.value)};
}
return {c_unknown, 0};
}
result op_or(result other) {
if (type == c_value && other.type == c_value) {
return result{c_value, uint16_t(value | other.value)};
}
return {c_unknown, 0};
}
result op_leftshift(result other) {
if (type == c_value && other.type == c_value) {
return result{c_value, uint16_t(value << other.value)};
}
return {c_unknown, 0};
}
result op_rightshift(result other) {
if (type == c_value && other.type == c_value) {
return result{c_value, uint16_t(value >> other.value)};
}
return {c_unknown, 0};
}
result op_not() {
if (type == c_value) {
return result{c_value, uint16_t(~value)};
}
return {c_unknown, 0};
}
};
struct cals {
std::map<line_view, std::pair<std::function<result()>, result>> calls;
bool is_value(line_view v, uint16_t* x) const noexcept {
const char* p = v.line;
while (p != v.line + v.length) {
if (*p >= '0' && *p <= '9') {
*x = *x * 10 + *p - '0';
p++;
} else {
return false;
}
}
return true;
}
result compute(line_view w) {
uint16_t x = 0;
if (is_value(w, &x)) {
return {result::c_value, x};
} else {
auto it = calls.find(w);
if (it != calls.end()) {
auto& r = it->second.second;
if (r.type == result::c_unknown) {
// std::cout << "compute " << w << std::endl;
auto& f = it->second.first;
r = f();
}
return r;
}
return {result::c_unknown, 0};
}
}
std::function<result()> op_and(line_view& x, line_view& y) {
return [&x, &y, this]() -> result { return compute(x).op_and(compute(y)); };
}
std::function<result()> op_or(line_view& x, line_view& y) {
return [&x, &y, this]() -> result { return compute(x).op_or(compute(y)); };
}
std::function<result()> op_leftshift(line_view& x, line_view& y) {
return [&x, &y, this]() -> result { return compute(x).op_leftshift(compute(y)); };
}
std::function<result()> op_rightshift(line_view& x, line_view& y) {
return [&x, &y, this]() -> result { return compute(x).op_rightshift(compute(y)); };
}
std::function<result()> op_not(line_view& x, line_view& y) {
return [&x, this]() -> result { return compute(x).op_not(); };
}
std::function<result()> op_value(line_view& x, line_view& y) {
return [&x, this]() -> result { return compute(x); };
}
std::function<result()> parse(line_view line, line_view* x, line_view* y, line_view* w) {
static struct _ {
std::function<result()> (cals::*op)(line_view&, line_view&);
const char* label;
} ops[] = {
{&cals::op_and, "AND"},
{&cals::op_or, "OR"},
{&cals::op_leftshift, "LSHIFT"},
{&cals::op_rightshift, "RSHIFT"},
};
const char* arrow = line.contains("->");
*w = line_view(arrow + 3, line.line + line.length);
for (auto op : ops) {
const char* p = line.contains(op.label);
if (p != nullptr) {
*x = line_view(line.line, p - 1);
*y = line_view(p + strlen(op.label) + 1, arrow - 1);
return (this->*op.op)(*x, *y);
}
}
const char* p = line.contains("NOT");
if (p != nullptr) {
*x = line_view(p + 4, arrow - 1);
return op_not(*x, *y);
}
*x = line_view(line.line, arrow - 1);
return op_value(*x, *y);
}
void parse(line_view line) {
line_view* x = new line_view();
line_view* y = new line_view();
line_view* w = new line_view();
auto f = parse(line, x, y, w);
auto p = calls.insert({*w, {f, {result::c_unknown, 0}}});
if (p.second == false) {
p.first->second = {f, {result::c_unknown, 0}};
}
}
};
result day7(line_view, const char*, const char* = nullptr);
} // namespace aoc2015
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