feat: add solution for smallest palindromic rearrangement ii

- add problem 3518 implementation
- add build configuration with debug and release modes
- add test cases and examples
- add makefile for problem-specific build workflow

3518/Makefile

@@ -0,0 +1,46 @@
+TARGET_NAME := smallest_palindromic_rearrangement_ii
+
+PROBLEM_ID := $(notdir $(CURDIR))
+
+BUILD_DIR := $(BUILD_ROOT)/$(PROBLEM_ID)
+
+TARGET := $(BUILD_DIR)/$(TARGET_NAME)
+
+SOURCES := \
+	main.cpp \
+	solution.cpp
+
+OBJECTS := $(SOURCES:%.cpp=$(BUILD_DIR)/%.o)
+
+
+all: build
+
+
+build: $(TARGET)
+
+
+$(TARGET): $(OBJECTS)
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) $^ $(LDFLAGS) -o $@
+
+
+$(BUILD_DIR)/%.o: %.cpp
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+
+run: build
+	$(TARGET)
+
+
+test: run
+
+
+clean:
+	rm -rf $(BUILD_DIR)
+
+
+rebuild: clean build
+
+
+.PHONY: all build run test clean rebuild