2 files changed, 31 insertions, 0 deletions
diff --git a/rushs/evalexpr/check_alphabet/check_alphabet.c b/rushs/evalexpr/check_alphabet/check_alphabet.c
new file mode 100644
index 0000000..fc540b4
--- /dev/null
+++ b/rushs/evalexpr/check_alphabet/check_alphabet.c
@@ -0,0 +1,25 @@
+#include "check_alphabet.h"
+
+#include <stddef.h>
+
+int check_alphabet(const char *str, const char *alphabet)
+{
+    if (alphabet == NULL || *alphabet == '\0')
+    {
+        return 1;
+    }
+
+    for (int i = 0; alphabet[i]; i++)
+    {
+        int j;
+        for (j = 0; str[j] && str[j] != alphabet[i]; j++)
+        {
+            continue;
+        }
+        if (str[j] == '\0')
+        {
+            return 0;
+        }
+    }
+    return 1;
+}
diff --git a/rushs/evalexpr/check_alphabet/check_alphabet.h b/rushs/evalexpr/check_alphabet/check_alphabet.h
new file mode 100644
index 0000000..667a20f
--- /dev/null
+++ b/rushs/evalexpr/check_alphabet/check_alphabet.h
@@ -0,0 +1,6 @@
+#ifndef CHECK_ALPHABET_H
+#define CHECK_ALPHABET_H
+
+int check_alphabet(const char *str, const char *alphabet);
+
+#endif /* !CHECK_ALPHABET_H */