1

.gitignore

@@ -1,5 +1,6 @@
 .venv
 /*.exe
+/*.dSYM
 
 # 忽略 linux 编译产物
 /*

.idea/workspace.xml

@@ -29,21 +29,11 @@
     </configurations>
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="4491295e-723c-4e0b-b7b4-9be1cbde5db8" name="更改" comment="fix gitignore">
+    <list default="true" id="4491295e-723c-4e0b-b7b4-9be1cbde5db8" name="更改" comment="1">
-      <change afterPath="$PROJECT_DIR$/.idea/codeStyles/codeStyleConfig.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/pojcs101_M02039_snakey_encryption.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/.idea/exercises.iml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/pojcs101_M02431_cows_gas_leak_WRONG.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01088_ski.cpp" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/pojcs101_M02524_ubiquitous_religions_dsu.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01088_ski_WRONG.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01321_chest_grid.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01328_radar_greedy.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01328_radar_greedy_WRONG.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01852_ants_falling.cpp" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pojcs101_M01922_ride_follower.cpp" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gitignore" beforeDir="false" afterPath="$PROJECT_DIR$/.gitignore" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/editor.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/editor.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/inspectionProfiles/Project_Default.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/inspectionProfiles/Project_Default.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pojcs101_M01002_memorable_number.cpp" beforeDir="false" afterPath="$PROJECT_DIR$/pojcs101_M01002_memorable_number.cpp" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -107,6 +97,8 @@
     "C/C++ 文件.pojcs101_M01328_radar_greedy.cpp.executor": "Debug",
     "C/C++ 文件.pojcs101_M01852_ants_falling.cpp.executor": "Run",
     "C/C++ 文件.pojcs101_M01922_ride_follower.cpp.executor": "Run",
+    "C/C++ 文件.pojcs101_M02039_snakey_encryption.cpp.executor": "Run",
+    "C/C++ 文件.pojcs101_M02431_cows_gas_leak.cpp.executor": "Debug",
     "C/C++ 文件.pojcs101_M02692.cpp.executor": "Run",
     "C/C++ 文件.pojcs101_M02692_12_coins.cpp.executor": "Run",
     "CMake 应用程序.exercises.executor": "Run",
@@ -138,7 +130,7 @@
       <recent name="$PROJECT_DIR$" />
     </key>
   </component>
-  <component name="RunManager" selected="C/C++ 文件.pojcs101_M01922_ride_follower.cpp">
+  <component name="RunManager" selected="C/C++ 文件.pojcs101_M02431_cows_gas_leak.cpp">
     <configuration name="pojcs101_M01328_radar_greedy.cpp" type="CppFileRunConfiguration" factoryName="CppFileRunConfiguration" temporary="true" REDIRECT_INPUT="false" ELEVATE="false" USE_EXTERNAL_CONSOLE="false" EMULATE_TERMINAL="false" PASS_PARENT_ENVS_2="true" PROJECT_NAME="exercises" TARGET_NAME="pojcs101_M01328_radar_greedy.cpp" CONFIG_NAME="pojcs101_M01328_radar_greedy.cpp">
       <option name="sourceFile" value="pojcs101_M01328_radar_greedy.cpp" />
       <method v="2">
@@ -157,8 +149,22 @@
         <option name="com.jetbrains.cidr.cpp.runfile.CppFileBuildBeforeRunTaskProvider$BasicBuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
+    <configuration name="pojcs101_M02039_snakey_encryption.cpp" type="CppFileRunConfiguration" factoryName="CppFileRunConfiguration" temporary="true" REDIRECT_INPUT="false" ELEVATE="false" USE_EXTERNAL_CONSOLE="false" EMULATE_TERMINAL="false" PASS_PARENT_ENVS_2="true" PROJECT_NAME="exercises" TARGET_NAME="pojcs101_M02039_snakey_encryption.cpp" CONFIG_NAME="pojcs101_M02039_snakey_encryption.cpp">
+      <option name="sourceFile" value="pojcs101_M02039_snakey_encryption.cpp" />
+      <method v="2">
+        <option name="com.jetbrains.cidr.cpp.runfile.CppFileBuildBeforeRunTaskProvider$BasicBuildBeforeRunTask" enabled="true" />
+      </method>
+    </configuration>
+    <configuration name="pojcs101_M02431_cows_gas_leak.cpp" type="CppFileRunConfiguration" factoryName="CppFileRunConfiguration" temporary="true" REDIRECT_INPUT="false" ELEVATE="false" USE_EXTERNAL_CONSOLE="false" EMULATE_TERMINAL="false" PASS_PARENT_ENVS_2="true" PROJECT_NAME="exercises" TARGET_NAME="pojcs101_M02431_cows_gas_leak.cpp" CONFIG_NAME="pojcs101_M02431_cows_gas_leak.cpp">
+      <option name="sourceFile" value="pojcs101_M02431_cows_gas_leak.cpp" />
+      <method v="2">
+        <option name="com.jetbrains.cidr.cpp.runfile.CppFileBuildBeforeRunTaskProvider$BasicBuildBeforeRunTask" enabled="true" />
+      </method>
+    </configuration>
     <recent_temporary>
       <list>
+        <item itemvalue="C/C++ 文件.pojcs101_M02431_cows_gas_leak.cpp" />
+        <item itemvalue="C/C++ 文件.pojcs101_M02039_snakey_encryption.cpp" />
         <item itemvalue="C/C++ 文件.pojcs101_M01922_ride_follower.cpp" />
         <item itemvalue="C/C++ 文件.pojcs101_M01852_ants_falling.cpp" />
         <item itemvalue="C/C++ 文件.pojcs101_M01328_radar_greedy.cpp" />

pojcs101_M02039_snakey_encryption.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+#include <string>
+#include <stdexcept>
+
+using namespace std;
+
+string decrypt_snakey(string encrypted, int col) {
+    string decrypted;
+    for (int i = 0; i < col; i++) {
+        for (int offset = 0;; offset++) {
+            try {
+                decrypted += encrypted.at(i + offset * 2 * col);
+                decrypted += encrypted.at((offset + 1) * 2 * col - i - 1);
+            } catch (out_of_range&) {
+                break;
+            }
+        }
+    }
+    return decrypted;
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    string encrypted;
+    int col;
+    cin >> col >> encrypted;
+    cout << decrypt_snakey(encrypted, col) << endl;
+
+    return 0;
+}

pojcs101_M02431_cows_gas_leak_WRONG.cpp

@@ -0,0 +1,55 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+typedef pair<int, int> Range;
+typedef pair<int, int> FuelStop;
+
+vector<Range> covered_ranges(const vector<FuelStop>& fuel_stops, const int full_distance, const int initial_fuel) {
+    vector<Range> ranges{{0, initial_fuel}};
+    ranges.reserve(fuel_stops.size());
+    for (const auto& [distance, fuel_amount] : fuel_stops) {
+        ranges.emplace_back(full_distance - distance, full_distance - distance + fuel_amount);
+    }
+    return ranges;
+}
+
+int min_stops(vector<Range> ranges, const int full_distance) {
+    sort(ranges.begin(), ranges.end());
+    int answer = 0;
+    int current_pos = 0, max_r = -1;
+    for (int i = 0; i < ranges.size();) {
+        if (ranges[i].first <= current_pos) {
+            max_r = max(max_r, ranges[i].second);
+            if (max_r >= full_distance) { return answer - 1; }
+            i++;
+        } else {
+            if (max_r < current_pos) { return -1; }
+            answer++, current_pos = max_r, max_r = -1;
+        }
+    }
+    return -1;
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    int fuel_stop_count, full_distance, initial_fuel;
+    cin >> fuel_stop_count;
+    vector<FuelStop> fuel_stops(fuel_stop_count);
+    for (int i = 0; i < fuel_stop_count; i++) {
+        cin >> fuel_stops[i].first >> fuel_stops[i].second;
+    }
+    cin >> full_distance >> initial_fuel;
+    const vector<Range> ranges = covered_ranges(fuel_stops, full_distance, initial_fuel);
+    for (const auto& [l, r] : ranges) {
+        clog << "[" << l << "," << r << "] ";
+    }
+    clog << endl;
+
+    cout << min_stops(ranges, full_distance) << endl;
+
+    return 0;
+}

pojcs101_M02524_ubiquitous_religions_dsu.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class Dsu {
+public:
+    struct Node {
+        size_t parent, size;
+    };
+
+    vector<Node> nodes;
+
+    explicit Dsu(const size_t size) : nodes(size) {
+        for (size_t i = 0; i < size; i++) {
+            nodes[i] = {.parent = i, .size = 0};
+        }
+    }
+
+    size_t find(const size_t x) {
+        if (nodes[x].parent == x) { return x; }
+        return nodes[x].parent = find(nodes[x].parent);
+    }
+
+    void unite(size_t x, size_t y) {
+        if ((x = find(x)) == (y = find(y))) { return; }
+        if (nodes[x].size > nodes[y].size) { swap(x, y); }
+        nodes[x].parent = y;
+        nodes[y].size += nodes[x].size;
+    }
+};
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    return 0;
+}