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#include "common.h"
#include <vector>
#include <deque>
namespace aoc2022 {
struct heightmap {
static const int row = 41;
static const int col = 66;
struct pos {
int x;
int y;
friend bool operator==(pos p1, pos p2) {
return p1.x == p2.x && p1.y == p2.y;
}
};
struct height {
char h;
int v = INT32_MAX;
};
height heights[row * col];
pos start;
pos end;
char& get(pos p) {
return heights[p.y * col + p.x].h;
}
int& was(pos p) {
return heights[p.y * col + p.x].v;
}
bool valid(pos p) {
return p.x >= 0 && p.x < col && p.y >= 0 && p.y < row;
}
void get_next(pos p, pos next[], int* n) {
pos ps[] = {
{p.x, p.y - 1}, // UP
{p.x, p.y + 1}, // DOWN
{p.x - 1, p.y}, // LEFT
{p.x + 1, p.y}, // RIGHT
};
for (int i = 0; i < 4; i++) {
if (valid(ps[i])) {
bool b1 = get(ps[i]) == get(p) + 1;
bool b2 = get(ps[i]) <= get(p);
if (b1 || b2) {
next[*n] = ps[i];
*n += 1;
}
}
}
}
void get_prev(pos p, pos prev[], int* n) {
pos ps[] = {
{p.x, p.y - 1}, // UP
{p.x, p.y + 1}, // DOWN
{p.x - 1, p.y}, // LEFT
{p.x + 1, p.y}, // RIGHT
};
for (int i = 0; i < 4; i++) {
if (valid(ps[i])) {
bool b1 = get(ps[i]) == get(p) - 1;
bool b2 = get(ps[i]) >= get(p);
if (b1 || b2) {
prev[*n] = ps[i];
*n += 1;
}
}
}
}
void flood(pos p) {
was(p) = 0;
std::deque<pos> q = {p};
while (!q.empty()) {
pos px = q.front();
q.pop_front();
pos next[4];
int n{0};
get_next(px, next, &n);
for (int i = 0; i < n; i++){
int x = was(px) + 1;
if (x < was(next[i])) {
was(next[i]) = x;
q.push_back(next[i]);
}
}
}
}
void flood_down(pos p, int* nearest) {
was(p) = 0;
std::deque<pos> q = {p};
while (!q.empty()) {
pos px = q.front();
q.pop_front();
if (get(px) == 'a') {
*nearest = was(px);
return;
}
pos prev[4];
int n{0};
get_prev(px, prev, &n);
for (int i = 0; i < n; i++) {
int x = was(px) + 1;
if (x < was(prev[i])) {
was(prev[i]) = x;
q.push_back(prev[i]);
}
}
}
}
void reset() {
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
was({j, i}) = INT32_MAX;
}
}
}
void print() {
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
printf("%c", get({j, i}));
}
printf("\n");
}
}
void load(int r, line_view lv) {
const char* p = lv.line;
for (int c = 0; c < col; c++) {
get({c, r}) = *(p + c);
if (*(p + c) == 'S') {
start = pos{c, r};
get({c, r}) = 'a';
}
if (*(p + c) == 'E') {
end = pos{c, r};
get({c, r}) = 'z';
}
}
}
};
std::pair<int, int> day12(line_view);
}
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