diff --git a/CMakeLists.txt b/CMakeLists.txt
index a3e6829..0a5498a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,3 +14,4 @@ add_subdirectory(rmdupfromsortedarray2)
 add_subdirectory(maxprofit2)
 add_subdirectory(canJump)
 add_subdirectory(jump)
+add_subdirectory(hindex)
diff --git a/Makefile b/Makefile
index ffbc5a2..186b690 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers
+SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers hindex
 
 all: $(SUBDIRS)
 
diff --git a/hindex/CMakeLists.txt b/hindex/CMakeLists.txt
new file mode 100644
index 0000000..0c5e55a
--- /dev/null
+++ b/hindex/CMakeLists.txt
@@ -0,0 +1,6 @@
+FILE(GLOB_RECURSE SOURCES src/*.cpp)
+
+add_executable(
+    hindex
+    ${SOURCES}
+)
diff --git a/hindex/Makefile b/hindex/Makefile
new file mode 100644
index 0000000..395d1ee
--- /dev/null
+++ b/hindex/Makefile
@@ -0,0 +1,17 @@
+CXX = g++
+CFLAGS = -Wall -g
+SRCS = $(wildcard src/*/*.cpp src/*.cpp)
+OBJS = $(SRCS:.cpp=.o)
+TARGET = hindex
+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)
diff --git a/hindex/meson.build b/hindex/meson.build
new file mode 100644
index 0000000..4b04ed7
--- /dev/null
+++ b/hindex/meson.build
@@ -0,0 +1 @@
+executable('hindex', 'src/main.cpp', install: true)
diff --git a/hindex/src/hindex.hpp b/hindex/src/hindex.hpp
new file mode 100644
index 0000000..eebc591
--- /dev/null
+++ b/hindex/src/hindex.hpp
@@ -0,0 +1,15 @@
+#include <vector>
+
+inline int hIndex(std::vector<int> &citations) {
+  int n = citations.size();
+  std::vector<int> count(n + 1, 0);
+  for (auto c : citations) {
+    c >= n ? count[n] += 1 : count[c] += 1;
+  }
+  int total = 0;
+  for (int i = n; i > -1; i--) {
+    total += count[i];
+    if (total >= i) return i;
+  }
+  return 0;
+}
diff --git a/hindex/src/main.cpp b/hindex/src/main.cpp
new file mode 100644
index 0000000..1f6061f
--- /dev/null
+++ b/hindex/src/main.cpp
@@ -0,0 +1,13 @@
+#include <cassert>
+#include <vector>
+#include "hindex.hpp"
+
+int main() {
+  std::vector<int> citations = {3, 0, 6, 1, 5};
+  int output = hIndex(citations);
+  assert(output == 3);
+  citations = {1, 3, 1};
+  output = hIndex(citations);
+  assert(output == 1);
+  return 0;
+}
diff --git a/meson.build b/meson.build
index 33592e2..cef21eb 100644
--- a/meson.build
+++ b/meson.build
@@ -8,3 +8,4 @@ subdir('rmdupfromsortedarray2')
 subdir('maxprofit2')
 subdir('canJump')
 subdir('jump')
+subdir('hindex')