solved: 504. Base 7

Signed-off-by: rajput-hemant <[email protected]>

Author: rajput-hemant

Diff for: src/0501-0600/504 - Base 7/base_7.rs

@@ -0,0 +1,23 @@
+impl Solution {
+    pub fn convert_to_base7(num: i32) -> String {
+        if num == 0 {
+            return "0".to_string();
+        }
+
+        let mut result = String::default();
+        let is_negative = num < 0;
+        let mut num = num.abs();
+
+        while num > 0 {
+            let rem = num % 7;
+            result.push_str(&rem.to_string());
+            num /= 7;
+        }
+
+        if is_negative {
+            result.push('-');
+        }
+
+        result.chars().rev().collect()
+    }
+}