72 lines
1.1 KiB
C++
72 lines
1.1 KiB
C++
#include <bits/stdc++.h>
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#include "../../include/aoc.hpp"
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using namespace std;
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unordered_map<icoord, unordered_map<int, int>> m;
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inline icoord posdir(int p) {
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switch (p) {
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case 0:
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return {0, 1};
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case 1:
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return {1, 0};
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case 2:
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return {0, -1};
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case 3:
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return {-1, 0};
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default:
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return {};
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}
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}
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void rec(icoord pos, int dir, int score) {
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if (!m.contains(pos)) {
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return;
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}
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auto &mp = m[pos];
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if (mp.contains(dir) && mp[dir] <= score) {
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return;
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}
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mp[dir] = score;
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rec(pos + posdir(dir), dir, score + 1);
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rec(pos, (dir + 1) & 3, score + 1000);
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rec(pos, (dir - 1) & 3, score + 1000);
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}
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int main() {
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ios::sync_with_stdio(0);
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cin.tie(0);
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icoord pos, s, e;
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string line;
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while (getline(cin, line) && !line.empty()) {
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for (pos.y = 0; pos.y < line.size(); pos.y++) {
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switch (line[pos.y]) {
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case '#':
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continue;
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case 'S':
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s = pos;
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break;
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case 'E':
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e = pos;
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break;
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}
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m[pos];
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}
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pos.x++;
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}
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rec(s, 0, 0);
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int minscore = -1;
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for (auto [dir, score] : m[e]) {
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if (minscore == -1 || score < minscore) {
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minscore = score;
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}
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}
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cout << minscore << '\n';
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}
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