diff --git a/src/math/complex.rs b/src/math/complex.rs
index 85713fe..7ecd960 100644
--- a/src/math/complex.rs
+++ b/src/math/complex.rs
@@ -51,7 +51,7 @@ macro_rules! impl_all {
     };
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 #[repr(C)]
 /// Complex
 pub struct Complex<T> {
@@ -135,3 +135,69 @@ where
         return write!(f, "({},{})", self.re, self.im);
     }
 }
+
+impl<T> From<(T, T)> for Complex<T> {
+    fn from(value: (T, T)) -> Self {
+        return Self {
+            re: value.0,
+            im: value.1,
+        };
+    }
+}
+
+#[cfg(test)]
+mod max_substring {
+    use std::hash::Hasher;
+
+    use super::*;
+    #[test]
+    fn create_new_complex() {
+        let a = Complex::new(1, 1);
+        assert_eq!(Complex { re: 1, im: 1 }, a);
+    }
+    #[test]
+    fn add() {
+        let a: Complex<i32> = (20, 30).into();
+        let b: Complex<i32> = (992, 8770).into();
+        assert_eq!(Complex { re: 1012, im: 8800 }, a + b);
+    }
+    #[test]
+    fn mul() {
+        let a: Complex<i32> = (20, 30).into();
+        let b: Complex<i32> = (992, 8770).into();
+        assert_eq!(
+            Complex {
+                re: -243260,
+                im: 205160
+            },
+            a * b
+        );
+    }
+    #[test]
+    fn div() {
+        let a: Complex<i32> = (20, 30).into();
+        let b: Complex<i32> = (992, 8770).into();
+        assert_eq!(Complex { re: 217, im: 112 }, b / a);
+    }
+    #[test]
+    fn sub() {
+        let a: Complex<i32> = (20, 30).into();
+        let b: Complex<i32> = (992, 8770).into();
+        assert_eq!(Complex { re: 972, im: 8740 }, b - a);
+    }
+    #[test]
+    fn hash() {
+        use std::collections::hash_map::DefaultHasher;
+        use std::hash::Hash;
+        fn calculate_hash<T: Hash>(t: &T) -> u64 {
+            let mut s = DefaultHasher::new();
+            t.hash(&mut s);
+            s.finish()
+        }
+        let a: Complex<i32> = (20, 30).into();
+        let b: Complex<i32> = (20, 40).into();
+        let c: Complex<i32> = (20, 30).into();
+        assert_eq!(calculate_hash(&a), calculate_hash(&c));
+        assert_eq!(calculate_hash(&a) == calculate_hash(&b), false);
+    }
+}