Add naive search algorithm

Author: danghai

searching/pattern_search/naive_search.c

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+
+/* Naive Pattern Search algorithm (brute force way) */
+void naive_search(char *str, char *pattern)
+{
+    int len_str = strlen(str);
+    int len_pat = strlen(pattern);
+
+    for(int i = 0; i <= len_str - len_pat; i++)
+    {
+        int j;
+        for(j = 0; j < len_pat; j++)
+        {
+            if(str[i + j] != pattern[j])
+                break;
+        }
+        if (j == len_pat)
+            printf("--Pattern is found at: %d\n", i);
+    }
+}
+
+int main()
+{
+    char str[] = "AABCAB12AFAABCABFFEGABCAB";
+    char pat1[] = "ABCAB";
+    char pat2[] = "FFF";    /* not found */
+    char pat3[] = "CAB";
+
+    printf("String test: %s\n", str);
+    printf("Test1: search pattern %s\n", pat1);
+    naive_search(str, pat1);
+    printf("Test2: search pattern %s\n", pat2);
+    naive_search(str, pat2);
+    printf("Test3: search pattern %s\n", pat3);
+    naive_search(str, pat3);
+    return 0;
+}