Task1 Init

files/hw2.txt

@@ -3,3 +3,8 @@
 ./hw2/simu1/QUESTIONS.md
 ./hw2/simu1/null.c
 
+./hw2/task1/README.md
+./hw2/task1/Cargo.toml
+./hw2/task1/tests/task1.rs
+./hw2/task1/src/lib.rs
+

hw2/task1/README.md

@@ -0,0 +1,40 @@
+# Homework hw2 task1
+
+## prepare your task
+
+Run the cargo command to prepare your task1/ directory as a library
+
+## task
+
+Calculate the Hamming difference between two DNA strands.
+
+A mutation is simply a mistake that occurs during the creation or
+copying of a nucleic acid, in particular DNA. Because nucleic acids are
+vital to cellular functions, mutations tend to cause a ripple effect
+throughout the cell. Although mutations are technically mistakes, a very
+rare mutation may equip the cell with a beneficial attribute. In fact,
+the macro effects of evolution are attributable by the accumulated
+result of beneficial microscopic mutations over many generations.
+
+The simplest and most common type of nucleic acid mutation is a point
+mutation, which replaces one base with another at a single nucleotide.
+
+By counting the number of differences between two homologous DNA strands
+taken from different genomes with a common ancestor, we get a measure of
+the minimum number of point mutations that could have occurred on the
+evolutionary path between the two strands.
+
+This is called the 'Hamming distance'.
+
+It is found by comparing two DNA strands and counting how many of the
+nucleotides are different from their equivalent in the other string.
+
+    GAGCCTACTAACGGGAT
+    CATCGTAATGACGGCCT
+    ^ ^ ^  ^ ^    ^^
+
+The Hamming distance between these two DNA strands is 7.
+
+
+
+

hw2/task1/tests/task1.rs

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+extern crate task1;
+
+#[test]
+fn test_no_difference_between_empty_strands() {
+    assert_eq!(task1::hamming_distance("", "").unwrap(), 0);
+}
+
+#[test]
+fn test_no_difference_between_identical_strands() {
+    assert_eq!(task1::hamming_distance("GGACTGA", "GGACTGA").unwrap(), 0);
+}
+
+#[test]
+fn test_complete_hamming_distance_in_small_strand() {
+    assert_eq!(task1::hamming_distance("ACT", "GGA").unwrap(), 3);
+}
+
+#[test]
+fn test_small_hamming_distance_in_the_middle_somewhere() {
+    assert_eq!(task1::hamming_distance("GGACG", "GGTCG").unwrap(), 1);
+}
+
+#[test]
+fn test_larger_distance() {
+    assert_eq!(task1::hamming_distance("ACCAGGG", "ACTATGG").unwrap(), 2);
+}
+
+#[test]
+fn test_first_string_is_longer() {
+    assert!(task1::hamming_distance("AAA", "AA").is_err());
+}
+
+#[test]
+fn test_second_string_is_longer() {
+    assert!(task1::hamming_distance("A", "AA").is_err());
+}