4 files changed, 40 insertions, 0 deletions
diff --git a/graphs/piscine/functional_programming/foldl.c b/graphs/piscine/functional_programming/foldl.c
new file mode 100644
index 0000000..ac222a7
--- /dev/null
+++ b/graphs/piscine/functional_programming/foldl.c
@@ -0,0 +1,11 @@
+#include "functional_programming.h"
+
+int foldl(int *array, size_t len, int (*func)(int, int))
+{
+    int acc = 0;
+    for (size_t i = 0; i < len; i++)
+    {
+        acc = (*func)(acc, array[i]);
+    }
+    return acc;
+}
diff --git a/graphs/piscine/functional_programming/foldr.c b/graphs/piscine/functional_programming/foldr.c
new file mode 100644
index 0000000..c232410
--- /dev/null
+++ b/graphs/piscine/functional_programming/foldr.c
@@ -0,0 +1,10 @@
+#include "functional_programming.h"
+
+int foldr(int *array, size_t len, int (*func)(int, int))
+{
+    if (len == 1)
+    {
+        return (*func)(array[0], 0);
+    }
+    return (*func)(array[0], foldr(array + 1, len - 1, func));
+}
diff --git a/graphs/piscine/functional_programming/functional_programming.h b/graphs/piscine/functional_programming/functional_programming.h
new file mode 100644
index 0000000..429b13c
--- /dev/null
+++ b/graphs/piscine/functional_programming/functional_programming.h
@@ -0,0 +1,10 @@
+#ifndef FUNCTIONAL_PROGRAMMING_H
+#define FUNCTIONAL_PROGRAMMING_H
+
+#include <stddef.h>
+
+void map(int *array, size_t len, void (*func)(int *));
+int foldr(int *array, size_t len, int (*func)(int, int));
+int foldl(int *array, size_t len, int (*func)(int, int));
+
+#endif /* !FUNCTIONAL_PROGRAMMING_H */
diff --git a/graphs/piscine/functional_programming/map.c b/graphs/piscine/functional_programming/map.c
new file mode 100644
index 0000000..311c39c
--- /dev/null
+++ b/graphs/piscine/functional_programming/map.c
@@ -0,0 +1,9 @@
+#include "functional_programming.h"
+
+void map(int *array, size_t len, void (*func)(int *))
+{
+    for (size_t i = 0; i < len; i++)
+    {
+        (*func)(array + i);
+    }
+}