Add legacy solutions

day10_1.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include "pystrlib.hpp"
+#include <algorithm>
+
+std::vector<int> list;
+int n = 256, skip_size, position;
+
+inline void rotate_left(int r) {
+    r %= n; if (r < 0) r += n;
+    list.insert(list.end(), list.begin(), list.begin() + r);
+    list.erase(list.begin(), list.begin() + r);
+}
+
+int main() {
+    freopen("day10.txt", "r", stdin);
+    for (int i = 0; i < n; ++i) list.push_back(i);
+    {
+        std::string line;
+        std::cin >> line;
+        for (const std::string &q : lib::split(line, ",")) {
+            int len = std::stoi(q);
+            std::reverse(list.begin(), list.begin() + len);
+            rotate_left(len + skip_size); position += len + skip_size++;
+        }
+    }
+    rotate_left(-position);
+    std::cout << list[0] * list[1] << std::endl;
+    return 0;
+}

day10_2.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include "pystrlib.hpp"
+#include <algorithm>
+#include <iomanip>
+
+std::vector<int> list, len;
+int n = 256, skip_size, position;
+
+inline void rotate_left(int r) {
+    r %= n; if (r < 0) r += n;
+    list.insert(list.end(), list.begin(), list.begin() + r);
+    list.erase(list.begin(), list.begin() + r);
+}
+
+void round() {
+    for (int i : len) {
+        std::reverse(list.begin(), list.begin() + i);
+        rotate_left(i + skip_size); position += i + skip_size++;
+    }
+}
+
+int main() {
+    freopen("day10.txt", "r", stdin);
+    for (int i = 0; i < n; ++i) list.push_back(i);
+    {
+        std::string line;
+        std::getline(std::cin, line);
+        for (char q : line)
+            len.push_back(q);
+        len.push_back(17);
+        len.push_back(31);
+        len.push_back(73);
+        len.push_back(47);
+        len.push_back(23);
+    }
+    for (int i = 0; i < 64; ++i)
+        round();
+    rotate_left(-position);
+    for (int i = 0; i < 256; i += 16) {
+        int s = 0;
+        for (int j = i; j < i + 16; ++j)
+            s ^= list[j];
+        std::cout << std::hex << std::setw(2) << std::setfill('0') << s;
+    }
+    std::cout << std::endl;
+    return 0;
+}

day11_1.cpp

@@ -0,0 +1,41 @@
+// se: (1, 0)
+// ne: (0, 1)
+// n: (-1, 1)
+// nw: (-1, 0)
+// sw: (0, -1)
+// s: (1, -1)
+
+// \|
+// -s-
+//  |\
+
+#include <iostream>
+#include "pystrlib.hpp"
+#include <cmath>
+
+constexpr int dx[6] = { 1, 0, -1, -1, 0, 1 }, dy[6] = { 0, 1, 1, 0, -1, -1 };
+int x, y;
+
+inline int get_d(const std::string &str) {
+    if (str == "se") return 0;
+    if (str == "ne") return 1;
+    if (str == "n") return 2;
+    if (str == "nw") return 3;
+    if (str == "sw") return 4;
+    if (str == "s") return 5;
+    return -1;
+}
+
+int main() {
+    freopen("day11.txt", "r", stdin);
+    {
+        std::string line; std::cin >> line;
+        std::vector<std::string> steps = lib::split(line, ",");
+        for (const std::string &str : steps) {
+            int d = get_d(str);
+            x += dx[d]; y += dy[d];
+        }
+    }
+    std::cout << ((x * y >= 0) ? (std::abs(x) + std::abs(y)) : (std::max(std::abs(x), std::abs(y)))) << std::endl;
+    return 0;
+}

day11_2.cpp

@@ -0,0 +1,44 @@
+// se: (1, 0)
+// ne: (0, 1)
+// n: (-1, 1)
+// nw: (-1, 0)
+// sw: (0, -1)
+// s: (1, -1)
+
+// \|
+// -s-
+//  |\
+
+#include <iostream>
+#include "pystrlib.hpp"
+#include <cmath>
+
+constexpr int dx[6] = { 1, 0, -1, -1, 0, 1 }, dy[6] = { 0, 1, 1, 0, -1, -1 };
+int x, y;
+
+inline int get_d(const std::string &str) {
+    if (str == "se") return 0;
+    if (str == "ne") return 1;
+    if (str == "n") return 2;
+    if (str == "nw") return 3;
+    if (str == "sw") return 4;
+    if (str == "s") return 5;
+    return -1;
+}
+
+int dist(int x, int y) { return (x * y >= 0) ? (std::abs(x) + std::abs(y)) : (std::max(std::abs(x), std::abs(y))); }
+
+int main() {
+    freopen("day11.txt", "r", stdin);
+    int ans = 0;
+    {
+        std::string line; std::cin >> line;
+        std::vector<std::string> steps = lib::split(line, ",");
+        for (const std::string &str : steps) {
+            int d = get_d(str);
+            x += dx[d]; y += dy[d]; ans = std::max(ans, dist(x, y));
+        }
+    }
+    std::cout << ans << std::endl;
+    return 0;
+}

day12_1.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+#include <queue>
+#include <numeric>
+#include "pystrlib.hpp"
+
+struct edge { int to, nxt; } g[20005];
+int head[2000], cnt;
+
+inline void add_edge(int f, int t) { g[++cnt] = (edge) { t, head[f] }; head[f] = cnt; }
+
+std::queue<int> Q;
+int V[2000], n;
+
+int main() {
+    freopen("day12.txt", "r", stdin);
+    {
+        std::string line;
+        while (std::getline(std::cin, line)) {
+            std::vector<std::string> to = lib::split(std::get<2>(lib::partition(line, " <-> ")), ", ");
+            for (const std::string &str : to) add_edge(n, std::stoi(str));
+            ++n;
+        }
+    }
+    Q.push(0); V[0] = 1;
+    while (!Q.empty()) {
+        int u = Q.front(); Q.pop();
+        for (int i = head[u]; i; i = g[i].nxt)
+            if (!V[g[i].to]) V[g[i].to] = 1, Q.push(g[i].to);
+    }
+    std::cout << std::accumulate(V, V + n, 0) << std::endl;
+    return 0;
+}

day12_2.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <queue>
+#include <numeric>
+#include "pystrlib.hpp"
+
+struct edge { int to, nxt; } g[20005];
+int head[2000], cnt;
+
+inline void add_edge(int f, int t) { g[++cnt] = (edge) { t, head[f] }; head[f] = cnt; }
+
+std::queue<int> Q;
+int V[2000], n;
+
+void bfs(int s) {
+    Q.push(s); V[s] = 1;
+    while (!Q.empty()) {
+        int u = Q.front(); Q.pop();
+        for (int i = head[u]; i; i = g[i].nxt)
+            if (!V[g[i].to]) V[g[i].to] = 1, Q.push(g[i].to);
+    }
+}
+
+int main() {
+    freopen("day12.txt", "r", stdin);
+    {
+        std::string line;
+        while (std::getline(std::cin, line)) {
+            std::vector<std::string> to = lib::split(std::get<2>(lib::partition(line, " <-> ")), ", ");
+            for (const std::string &str : to) add_edge(n, std::stoi(str));
+            ++n;
+        }
+    }
+    int ans = 0;
+    for (int i = 0; i < n; ++i)
+        if (!V[i]) ++ans, bfs(i);
+    std::cout << ans << std::endl;
+    return 0;
+}

day13_1.cpp

@@ -0,0 +1,18 @@
+#include <iostream>
+#include "pystrlib.hpp"
+#include <utility>
+
+int main() {
+    freopen("day13.txt", "r", stdin);
+    int ans = 0;
+    {
+        std::string line;
+        while (std::getline(std::cin, line)) {
+            auto [D, _, R] = lib::partition(line, ": ");
+            int d = std::stoi(D), r = std::stoi(R);
+            !(d % ((r - 1) << 1)) && (ans += d * r);
+        }
+    }
+    std::cout << ans << std::endl;
+    return 0;
+}

day13_2.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+#include "pystrlib.hpp"
+#include <utility>
+
+std::vector< std::pair<int, int> > wall;
+
+bool pass(int x) {
+    for (const auto &[d, r] : wall)
+        if (!((x + d) % r)) return false;
+    return true;
+}
+
+int main() {
+    freopen("day13.txt", "r", stdin);
+    {
+        std::string line;
+        while (std::getline(std::cin, line)) {
+            auto [D, _, R] = lib::partition(line, ": ");
+            wall.emplace_back(std::stoi(D), (std::stoi(R) - 1) << 1);
+        }
+    }
+    for (int i = 0; ; ++i)
+        if (pass(i)) { std::cout << i << std::endl; return 0; }
+}

day14_1.cpp

@@ -0,0 +1,61 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <bitset>
+
+namespace hash {
+
+std::vector<int> list, len;
+int n = 256, skip_size, position;
+
+inline void rotate_left(int r) {
+    r %= n; if (r < 0) r += n;
+    list.insert(list.end(), list.begin(), list.begin() + r);
+    list.erase(list.begin(), list.begin() + r);
+}
+
+void round() {
+    for (int i : len) {
+        std::reverse(list.begin(), list.begin() + i);
+        rotate_left(i + skip_size); position += i + skip_size++;
+    }
+}
+
+std::bitset<128> hash(const std::string &str) {
+    list.clear(); len.clear(); skip_size = 0; position = 0;
+    for (int i = 0; i < n; ++i) list.push_back(i);
+    {
+        for (char q : str)
+            len.push_back(q);
+        len.push_back(17);
+        len.push_back(31);
+        len.push_back(73);
+        len.push_back(47);
+        len.push_back(23);
+    }
+    for (int i = 0; i < 64; ++i)
+        round();
+    rotate_left(-position);
+    std::bitset<128> final;
+    for (int i = 0; i < 256; i += 16) {
+        int s = 0, p = i >> 1;
+        for (int j = i; j < i + 16; ++j)
+            s ^= list[j];
+        for (int j = p + 7; j >= p; --j)
+            final[j] = s & 1, s >>= 1;
+    }
+    return final;
+}
+
+}
+
+std::string key;
+int ans;
+
+int main() {
+    std::cin >> key; key += "-";
+    for (int i = 0; i < 128; ++i)
+        ans += hash::hash(key + std::to_string(i)).count();
+    std::cout << ans << std::endl;
+    return 0;
+}