add: 230403

cpp/2304/230403.cpp

@@ -0,0 +1,47 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+/**
+ * 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) {
+		std::vector<uint16_t> bucket(30005);
+		for (int i : people)
+			++bucket[i];
+        int ans = bucket[limit], i = 1, j = limit - 1, delta;
+        for (; i < j; --j) {
+            if (!bucket[j])
+                continue;
+            while (bucket[j] && i + j <= limit && i < j) {
+                delta = std::min(bucket[j], bucket[i]);
+                bucket[j] -= delta;
+                bucket[i] -= delta;
+                ans += delta;
+                if (!bucket[i])
+                    ++i;
+            }
+            if (bucket[j]) {
+				if (i == j && i + j <= limit)
+					ans += (bucket[i] >> 1) + (bucket[i] & 1);
+				else
+					ans += bucket[j];
+			}
+            bucket[j] = 0;
+        }
+        if (bucket[i])
+            ans += (bucket[i] >> 1) + (bucket[i] & 1);
+        return ans;
+	}
+};
+
+int main() {
+    std::cout << Solution::numRescueBoats({2,2}, 6);
+    return 0;
+}

cpp/2304/CMakeLists.txt

@@ -4,4 +4,4 @@ PROJECT(2304)
 SET(CMAKE_CXX_STANDARD 23)
 SET(CMAKE_EXPORT_COMPILE_COMMANDS true)
 
-ADD_EXECUTABLE(2304 230402.cpp)
+ADD_EXECUTABLE(2304 230403.cpp)