feat: add brute force string searching (#694)

* feat: add brute force string searching algorithm

* feat: add brute force string searching algorithm

strings/brute_force_string_searching.cpp

@@ -0,0 +1,52 @@
+#include  <iostream>
+#include  <string>
+#include  <vector>
+
+using std::string;
+
+int brute_force(string text, string pattern);
+std::vector<std::vector<string>> test_set  =   {
+    // {text, pattern, expected output}
+     {"a", "aa", "-1"},
+     {"a", "a", "0"},
+     {"ba", "b", "0"},
+     {"bba", "bb", "0"},
+     {"bbca", "c", "2"},
+     {"ab", "b", "1"}
+};
+
+int main() {
+    for  (size_t i  =  0 ;  i < test_set.size();  i++) {
+        int output  =  brute_force(test_set[i][0],  test_set[i][1]);
+        if (std::to_string(output)  ==  test_set[i][2])
+            std::cout  <<  "success\n";
+        else
+            std::cout  <<  "failure\n";
+    }
+    return 0;
+}
+
+/*
+ *@description    Find a pattern in a string by comparing the pattern
+ *                to every substring.
+ *@param text     Any string that might contain the pattern.
+ *@param pattern  String that we are searching for.
+ *@return       Index where the pattern starts in the text or
+ *                -1 if the pattern was not found.
+ */
+
+int brute_force(string text, string pattern) {
+    size_t pat_l  =  pattern.length();
+    size_t txt_l  =  text.length();
+    int index  =  -1;
+    if (pat_l  <=  txt_l) {
+        for  (size_t i = 0;  i < txt_l-pat_l+1; i++) {
+            string s  =  text.substr(i, pat_l);
+            if (s  ==  pattern) {
+                index  =  i;
+                break;
+            }
+        }
+    }
+    return index;
+}