d3001612b2
Axum + SQLite full-stack copy of the ZenithPrep PYQ practice app. Paper builder with unseen-question exclusion, timed CBT screen with palette and autosave, +4/-1 grading with numerical tolerance, per-question analysis, history, dashboard with weak-subtopic tracking and coach notes.
95 lines
No EOL
2.5 KiB
Rust
95 lines
No EOL
2.5 KiB
Rust
// Grading rules: MCQ comparison, numerical tolerance, and the +4 / −1 scheme.
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use std::collections::HashMap;
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#[derive(Clone, Debug, PartialEq)]
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struct Q {
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qtype: &'static str,
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answer: String,
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}
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fn numerical_ok(selected: &str, answer: &str) -> bool {
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let s: f64 = match selected.trim().parse() {
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Ok(v) => v,
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Err(_) => return false,
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};
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let a: f64 = match answer.trim().parse() {
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Ok(v) => v,
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Err(_) => return false,
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};
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let tol = a.abs() * 1e-3 + 1e-6;
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(s - a).abs() <= tol
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}
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fn is_correct(q: &Q, selected: &str) -> bool {
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if selected.trim().is_empty() {
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return false;
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}
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if q.qtype == "NUM" {
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numerical_ok(selected, &q.answer)
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} else {
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selected.trim().eq_ignore_ascii_case(q.answer.trim())
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}
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}
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fn marks(q: &Q, selected: &str) -> i32 {
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if selected.trim().is_empty() {
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0
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} else if is_correct(q, selected) {
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4
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} else {
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-1
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}
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}
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#[test]
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fn mcq_is_case_insensitive_and_trimmed() {
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let q = Q { qtype: "MCQ", answer: "A".into() };
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assert!(is_correct(&q, "a"));
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assert!(is_correct(&q, " A "));
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assert!(!is_correct(&q, "B"));
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}
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#[test]
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fn blank_answer_is_wrong_not_skipped() {
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let q = Q { qtype: "MCQ", answer: "A".into() };
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assert_eq!(marks(&q, ""), 0, "a blank question scores zero, not minus one");
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assert_eq!(marks(&q, " "), 0);
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}
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#[test]
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fn wrong_answer_costs_one_mark() {
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let q = Q { qtype: "MCQ", answer: "A".into() };
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assert_eq!(marks(&q, "C"), -1);
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}
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#[test]
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fn correct_answer_scores_four() {
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let q = Q { qtype: "MCQ", answer: "A".into() };
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assert_eq!(marks(&q, "A"), 4);
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}
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#[test]
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fn numerical_answers_allow_small_float_error() {
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let q = Q { qtype: "NUM", answer: "20".into() };
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assert!(is_correct(&q, "20.0"));
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assert!(is_correct(&q, "20.01"), "within 0.1 percent tolerance");
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assert!(!is_correct(&q, "20.5"), "outside tolerance");
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assert!(!is_correct(&q, "abc"), "non numeric input is wrong");
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}
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#[test]
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fn zero_answer_is_not_mistaken_for_blank() {
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let q = Q { qtype: "NUM", answer: "0".into() };
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assert!(is_correct(&q, "0"));
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assert_eq!(marks(&q, "0"), 4);
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}
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#[test]
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fn mixed_paper_score_matches_hand_calculation() {
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let mut answers = HashMap::new();
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answers.insert(1i64, ("A".to_string(), 4)); // correct
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answers.insert(2i64, ("B".to_string(), -1)); // wrong
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answers.insert(3i64, (String::new(), 0)); // blank
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let total: i32 = answers.values().map(|(_, m)| m).sum();
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assert_eq!(total, 3);
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} |