Added solution of problem 179

Author: kurpenok

src/solutions/mod.rs

@@ -96,6 +96,7 @@ pub mod s0165_compare_version_numbers;
 pub mod s0167_two_sum_ii_input_array_is_sorted;
 pub mod s0172_factorial_trailing_zeroes;
 pub mod s0173_binary_search_tree_iterator;
+pub mod s0179_largest_number;
 pub mod s0231_power_of_two;
 pub mod s0232_implement_queue_using_stacks;
 pub mod s0234_palindrome_linked_list;

src/solutions/s0179_largest_number.rs

@@ -0,0 +1,30 @@
+pub fn largest_number(nums: Vec<i32>) -> String {
+    let mut num_strs: Vec<String> = nums.into_iter().map(|num| num.to_string()).collect();
+    num_strs.sort_by(|a, b| {
+        let order1 = format!("{}{}", a, b);
+        let order2 = format!("{}{}", b, a);
+        order2.cmp(&order1)
+    });
+
+    let result = num_strs.join("");
+    if result.starts_with('0') {
+        "0".to_string()
+    } else {
+        result
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_case_1() {
+        assert_eq!(largest_number(vec![10, 2]), "210");
+    }
+
+    #[test]
+    fn test_case_2() {
+        assert_eq!(largest_number(vec![3, 30, 34, 5, 9]), "9534330");
+    }
+}