Add Perfect Square (#576)

Author: cyrixninja

src/math/perfect_square.rs

@@ -0,0 +1,59 @@
+// Author : cyrixninja
+// Perfect Square : Checks if a number is perfect square number or not
+// https://en.wikipedia.org/wiki/Perfect_square
+fn perfect_square(num: i32) -> bool {
+    if num < 0 {
+        return false;
+    }
+    let sqrt_num = (num as f64).sqrt() as i32;
+    sqrt_num * sqrt_num == num
+}
+
+fn perfect_square_binary_search(n: i32) -> bool {
+    if n < 0 {
+        return false;
+    }
+
+    let mut left = 0;
+    let mut right = n;
+    
+    while left <= right {
+        let mid = (left + right) / 2;
+        let mid_squared = mid * mid;
+
+        if mid_squared == n {
+            return true;
+        } else if mid_squared > n {
+            right = mid - 1;
+        } else {
+            left = mid + 1;
+        }
+    }
+
+    false
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_perfect_square() {
+        assert!(perfect_square(9) == true);
+        assert!(perfect_square(81) == true);
+        assert!(perfect_square(4) == true);
+        assert!(perfect_square(0) == true);
+        assert!(perfect_square(3) == false);
+        assert!(perfect_square(-19) == false);
+    }
+
+    #[test]
+    fn test_perfect_square_binary_search() {
+        assert!(perfect_square_binary_search(9) == true);
+        assert!(perfect_square_binary_search(81) == true);
+        assert!(perfect_square_binary_search(4) == true);
+        assert!(perfect_square_binary_search(0) == true);
+        assert!(perfect_square_binary_search(3) == false);
+        assert!(perfect_square_binary_search(-19) == false);
+    }
+}