Init task3

hw2/task3/README.md

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+# Homework hw2 task3
+
+## prepare your task
+
+Run the cargo command to prepare your task3/ directory as a library
+
+## task
+
+Compute Pascal's triangle up to a given number of rows. Create the new type *PascalsTriangle* and implement the methods *new()* and *rows()*. See the `tests/task3.rs` for more informationen about parameters and returns of the methods.
+
+In Pascal's Triangle each number is computed by adding the numbers to
+the right and left of the current position in the previous row.
+
+```plain
+    1
+   1 1
+  1 2 1
+ 1 3 3 1
+1 4 6 4 1
+# ... etc
+```
+
+
+
+

hw2/task3/tests/task3.rs

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+extern crate task3;
+
+use task3::*;
+
+#[test]
+fn no_rows() {
+    let pt = PascalsTriangle::new(0);
+    let expected: Vec<Vec<u32>> = Vec::new();
+    assert_eq!(expected, pt.rows());
+}
+
+
+#[test]
+fn one_row() {
+    let pt = PascalsTriangle::new(1);
+    let expected: Vec<Vec<u32>> = vec![vec![1]];
+    assert_eq!(expected, pt.rows());
+}
+
+#[test]
+fn two_rows() {
+    let pt = PascalsTriangle::new(2);
+    let expected: Vec<Vec<u32>> = vec![vec![1], vec![1, 1]];
+    assert_eq!(expected, pt.rows());
+}
+
+#[test]
+fn three_rows() {
+    let pt = PascalsTriangle::new(3);
+    let expected: Vec<Vec<u32>> = vec![vec![1], vec![1, 1], vec![1, 2, 1]];
+    assert_eq!(expected, pt.rows());
+}
+
+#[test]
+fn last_of_four_rows() {
+    let pt = PascalsTriangle::new(4);
+    let expected: Vec<u32> = vec![1, 3, 3, 1];
+    assert_eq!(expected, pt.rows().pop().unwrap());
+}