added trivia algos

Author: lerabela

Sorting/trivia/sort_using_index.php

@@ -0,0 +1,60 @@
+<?php
+
+/**
+ * Function will sort array using a predicate index
+ */
+
+function index_sort(array &$sort, int $idx): array{
+
+    try{
+
+        if(empty($sort) || count($sort) == 0){
+
+            throw new \Exception("Invalid array, please check array and try again");
+
+        }
+
+        uasort($sort, function($val_1, $val_2) use($idx) {
+
+            if(!ctype_alpha($val_1) || !ctype_alpha($val_2)){
+
+                return null;
+
+            }
+
+            if(substr($val_1, $idx) > substr($val_2, $idx)){
+
+                return 1;
+
+            }else if( substr($val_1, $idx) < substr($val_2, $idx) ){
+
+                return -1;
+
+            }
+
+            return null;
+
+        });
+
+        return $sort;
+
+    }catch(\Exception $e){
+
+        exit($e->getMessage());
+        echo "\n\n";
+
+    }
+
+}
+
+$arr = ['orange', 'banana', 'apple','carrot', 'collard', 'pea'];
+
+$sorted = index_sort($arr, 2);
+
+foreach($sorted as $val){
+
+    echo $val . " ";
+
+}
+
+echo "\n\n";

Sorting/trivia/sort_using_last_char.php

@@ -0,0 +1,60 @@
+<?php
+
+/**
+ * Function will sort array using last char in string
+ */
+
+function sort_last_char(array &$usort): array{
+
+    try{
+
+        if(empty($usort) || count($usort) == 0){
+
+            throw new \Exception("Invalid array, please check array and try agaian");
+
+        }
+
+        uasort($usort,function($val_1, $val_2) {
+
+            if(!ctype_alpha($val_1) || !ctype_alpha($val_2)){
+
+                return null;
+    
+            }    
+
+            if(substr($val_1,-1) > substr($val_2,-1)){
+
+                return 1;
+
+            }else if(substr($val_1,-1) < substr($val_2,-1)){
+
+                return -1;
+
+            }
+
+            return null;
+
+        });
+
+        return $usort;
+
+    }catch(\Exception $e){
+
+        exit($e->getMessage());
+        echo "\n\n\n\n";
+
+    }
+
+}
+
+$arr = ['orange', 'banana', 'apple','carrot', 'collard', 'pea'];
+
+$sorted_arr = sort_last_char($arr);
+
+foreach($sorted_arr as $val){
+
+    echo $val . " ";
+
+}
+
+echo "\n\n\n\n";