added candy

CMakeLists.txt

@@ -18,3 +18,4 @@ add_subdirectory(hindex)
 add_subdirectory(randomizedset)
 add_subdirectory(productExceptSelf)
 add_subdirectory(canCompleteCircuit)
+add_subdirectory(candy)

Makefile

@@ -1,4 +1,4 @@
-SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers hindex randomizedset productExceptSelf canCompleteCircuit
+SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers hindex randomizedset productExceptSelf canCompleteCircuit candy
 
 all: $(SUBDIRS)
 

candy/CMakeLists.txt

@@ -0,0 +1,6 @@
+FILE(GLOB_RECURSE SOURCES src/*.cpp)
+
+add_executable(
+    candy
+    ${SOURCES}
+)

candy/Makefile

@@ -0,0 +1,17 @@
+CXX = g++
+CFLAGS = -Wall -g -std=c++20
+SRCS = $(wildcard src/*/*.cpp src/*.cpp)
+OBJS = $(SRCS:.cpp=.o)
+TARGET = candy
+CROSS_COMPILE =
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CROSS_COMPILE)$(CXX) $(LDFLAGS) $^ -o $@ $(LIBS)
+
+%.o: %.cpp
+	$(CROSS_COMPILE)$(CXX) $(CFLAGS) $(INCLUDES) -c $< -o $@
+
+clean:
+	rm -f $(OBJS) $(TARGET)

candy/meson.build

@@ -0,0 +1 @@
+executable('candy', 'src/main.cpp', install: true)

candy/src/candy.hpp

@@ -0,0 +1,19 @@
+#include <numeric>
+#include <vector>
+
+inline int candy(std::vector<int> &ratings) {
+  int n = ratings.size();
+  if (n == 0) return 0;
+  std::vector<int> candies(n, 1);
+  for (int i = 1; i < n; i++) {
+    if (ratings[i] > ratings[i - 1]) {
+      candies[i] = candies[i - 1] + 1;
+    }
+  }
+  for (int i = n - 2; i >= 0; i--) {
+    if (ratings[i] > ratings[i + 1]) {
+      candies[i] = std::max(candies[i], candies[i + 1] + 1);
+    }
+  }
+  return std::accumulate(candies.begin(), candies.end(), 0);
+}

candy/src/main.cpp

@@ -0,0 +1,14 @@
+#include <cassert>
+#include <vector>
+#include "candy.hpp"
+
+int main() {
+  std::vector<int> ratings = {1, 0, 2};
+  int output = candy(ratings);
+  assert(output == 5);
+
+  ratings = {1, 2, 2};
+  output = candy(ratings);
+  assert(output == 4);
+  return 0;
+}

meson.build

@@ -12,3 +12,4 @@ subdir('hindex')
 subdir('randomizedset')
 subdir('productExceptSelf')
 subdir('canCompleteCircuit')
+subdir('candy')