feat: add display trait to matrix

src/types/matrix.rs

@@ -1,10 +1,32 @@
-use std::str::FromStr;
+use std::{fmt::Display, str::FromStr};
 /// Matrix
 pub struct Matrix {
     pub nrows: usize,
     pub ncols: usize,
     pub data: Vec<Vec<i32>>,
 }
+impl Display for Matrix {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut builder = String::new();
+        for (i, r) in self.data.iter().enumerate() {
+            let mut row_str = if i == 0 || i == self.nrows - 1 {
+                "+".to_string()
+            } else {
+                "|".to_string()
+            };
+            for (j, n) in r.iter().enumerate() {
+                row_str += &format!("{}{}", n, if j == self.ncols - 1 { "" } else { "," });
+            }
+            row_str += if i == 0 || i == self.nrows - 1 {
+                "+\n"
+            } else {
+                "|\n"
+            };
+            builder += &row_str;
+        }
+        write!(f, "{}", builder)
+    }
+}
 impl Matrix {
     pub fn new(data: Vec<Vec<i32>>) -> Matrix {
         Matrix {