add: 220324 [cpp]

cpp/2203/220324.cpp

@@ -0,0 +1,43 @@
+#include <vector>
+#include <algorithm>
+
+/**
+ * 881. Boats to Save People
+ * You are given an array people where people[i] is the weight of the ith person, and an infinite number of boats where each boat can carry a maximum weight of limit. Each boat carries at most two people at the same time, provided the sum of the weight of those people is at most limit.
+ * Return the minimum number of boats to carry every given person.
+ */
+
+class Solution {
+public:
+	static int numRescueBoats(const std::vector<int>& people, int limit) {
+		int cnt[30005]{};
+		for (int i : people)
+			++cnt[i];
+		int L = 0, R = 30004, ret = 0;
+		for (; L <= R; ++ret) {
+			while (!cnt[L] && L <= R)
+				++L;
+			while (!cnt[R] && L <= R)
+				--R;
+			if (!cnt[R])
+				break;
+			--cnt[R];
+			if (cnt[L] && L + R <= limit)
+				--cnt[L];
+		}
+		return ret;
+	}
+};
+
+class SolutionOld {
+public:
+	static int numRescueBoats(std::vector<int>& people, int limit) {
+		std::sort(people.begin(), people.end());
+		int ret = 0, L = 0, R = people.size() - 1;
+		for (; L <= R; ++ret, --R) {
+			if (people[R] + people[L] <= limit)
+				++L;
+		}
+		return ret;
+	}
+};

cpp/2203/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2203)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2203 220322.cpp)
+ADD_EXECUTABLE(2203 220324.cpp)