Find The Number of Ways to Place People II

CMakeLists.txt

@@ -531,6 +531,7 @@ add_task(find-the-middle-index-in-array)
 add_task(find-the-minimum-and-maximum-number-of-nodes-between-critical-points)
 add_task(find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k)
 add_task(find-the-number-of-ways-to-place-people-i)
+add_task(find-the-number-of-ways-to-place-people-ii)
 add_task(find-the-original-array-of-prefix-xor)
 add_task(find-the-peaks)
 add_task(find-the-pivot-integer)

PROBLEM_LIST.md

@@ -1864,3 +1864,4 @@
 | 3024. | [Type of Triangle II](https://leetcode.com/problems/type-of-triangle-ii/) | [C++](./solutions/type-of-triangle-ii/solution.hpp) | <img src='https://img.shields.io/badge/Easy-darkgreen?style=flat-square'/> | O(1) / O(1)|  |  |
 | 3025. | [Find the Number of Ways to Place People I](https://leetcode.com/problems/find-the-number-of-ways-to-place-people-i/) | [C++](./solutions/find-the-number-of-ways-to-place-people-i/solution.hpp) | <img src='https://img.shields.io/badge/Medium-darkorange?style=flat-square'/> | O(N<sup>3</sup>) / O(1)|  |  |
 | 3026. | [Maximum Good Subarray Sum](https://leetcode.com/problems/maximum-good-subarray-sum/) | [C++](./solutions/maximum-good-subarray-sum/solution.hpp) | <img src='https://img.shields.io/badge/Medium-darkorange?style=flat-square'/> | O(N) / O(N)|  |  |
+| 3027. | [Find the Number of Ways to Place People II](https://leetcode.com/problems/find-the-number-of-ways-to-place-people-ii/) | [C++](./solutions/find-the-number-of-ways-to-place-people-ii/solution.hpp) | <img src='https://img.shields.io/badge/Hard-darkred?style=flat-square'/> | O(N<sup>2</sup>) / O(N)|  |  |

solutions/find-the-number-of-ways-to-place-people-ii/CMakeLists.txt

@@ -0,0 +1 @@
+add_catch(test_find_the_number_of_ways_to_place_people_ii test.cpp)

solutions/find-the-number-of-ways-to-place-people-ii/solution.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <climits>
+#include <ranges>
+#include <vector>
+
+// Time: O(N^2)
+// Space: O(N)
+
+class Solution {
+public:
+  static int numberOfPairs(std::vector<std::vector<int>> points) {
+    std::ranges::sort(points, [](auto &lhs, auto &rhs) {
+      return std::tie(lhs[1], rhs[0]) > std::tie(rhs[1], lhs[0]);
+    });
+
+    int ans = 0;
+    for (size_t i = 0; i < points.size(); ++i) {
+      auto minx = INT_MAX;
+      for (size_t j = i + 1; j < points.size(); ++j) {
+        if (points[j][0] >= points[i][0] && points[j][0] < minx) {
+          ++ans;
+          minx = std::min(minx, points[j][0]);
+        }
+      }
+    }
+    return ans;
+  }
+};

solutions/find-the-number-of-ways-to-place-people-ii/test.cpp

@@ -0,0 +1,30 @@
+#include <catch.hpp>
+
+#include <solution.hpp>
+
+TEST_CASE("Simple") {
+  struct TestCase {
+    std::vector<std::vector<int>> points;
+    int expected;
+  };
+
+  std::vector<TestCase> test_cases{
+      {
+          .points{{1, 1}, {2, 2}, {3, 3}},
+          .expected = 0,
+      },
+      {
+          .points{{6, 2}, {4, 4}, {2, 6}},
+          .expected = 2,
+      },
+      {
+          .points{{3, 1}, {1, 3}, {1, 1}},
+          .expected = 2,
+      },
+  };
+
+  for (const auto &[points, expected] : test_cases) {
+    const auto actual = Solution::numberOfPairs(points);
+    REQUIRE(expected == actual);
+  }
+}