我希望计算我的代码在多次测试运行中平均执行的时间。在每次测试运行中,doWork()
执行我想要的时间工作。但我也想在每次测试中checkWork()
,而不计算时间。我将有许多类似的练习#类,所以我想通过TestInterface抽象测试。我目前的方式是否合理?或者是否有更好的设计模式/标准方法?提前谢谢。
@FunctionalInterface
public interface TestInterface {
void test(final int NUM_TESTS);
}
public class TimeTests {
public static void test(TestInterface ti, final int NUM_TESTS, String testName) {
DecimalFormat df = new DecimalFormat("#.####");
long start = System.nanoTime();
ti.test(NUM_TESTS);
System.out.println("DEBUG: " + testName + " took "
+ df.format((System.nanoTime() - start) * 1.0 / NUM_TESTS)
+ " nanoseconds on average for " + NUM_TESTS + " tests");
}
}
public class Exercise1 {
private static final int NUM_TESTS = (int) Math.pow(10, 6);
private static void mainWork(List<Integer> A) {
// do stuff and time it
}
private static void checkWork(List<Integer> A) {
// do stuff but don't count it towards the time
}
public static void main(String[] args) {
TimeTests.test((NUM_TESTS_LOCAL) -> {
for (int i = 0; i < NUM_TESTS_LOCAL; ++i) {
List<Integer> A = new ArrayList<>();
// add random elements to A
mainWork(A);
checkWork(A);
}
}, NUM_TESTS, "Exercise1");
}
}
答案 0 :(得分:0)
好吧,我认为我设法为这项任务整理了一个体面的框架(这是正确的词吗?)。如果有人可以插手让我知道我的方法是否有用,我真的很感激。
虽然到目前为止我的代码似乎对我的用例很好,但我有几个问题:
public interface CloneableTestInput<T extends CloneableTestInput<T>>
的接口定义中,类型模板<T extends CloneableTestInput<T>
如何不是循环定义?我不确定我完全理解该类型模板的用语。CloneableList
的通用CloneableTestInput<List>
类?目前,我需要为每个Collection类型(例如ArrayList,LinkedList,...)单独实现。同样,是否可以创建实现CloneableSet
?CloneableTestInput<Set>
类
醇>
提前致谢:)
这允许TimeTests.java
适用于通用输入类型。
public interface CloneableTestInput<T extends CloneableTestInput<T>> extends Cloneable {
T clone();
}
public class CloneableString implements CloneableTestInput<CloneableString> {
public String data;
public CloneableString() {}
public CloneableString(String input) { data = input; }
public CloneableString clone() { return new CloneableString(String.valueOf(data)); }
}
public class CloneableArrayList extends ArrayList implements CloneableTestInput<CloneableArrayList> {
public CloneableArrayList(ArrayList input) {
this.addAll(input);
}
@Override
public CloneableArrayList clone() {
return new CloneableArrayList(this);
}
}
@FunctionalInterface
public interface TimeTestsInterface<outputType> {
void test(Callable<CloneableTestInput> formInput
, Function<CloneableTestInput, outputType> runAlgorithm
, Function<CloneableTestInput, outputType> getKnownOutput
, BiFunction<outputType, outputType, Boolean> checkResults
, final int NUM_TESTS, String testName);
}
public class TimeTests<outputType> implements TimeTestsInterface<outputType> {
public void test(Callable<CloneableTestInput> formInput
, Function<CloneableTestInput, outputType> runAlgorithm
, Function<CloneableTestInput, outputType> getKnownOutput
, BiFunction<outputType, outputType, Boolean> checkResults
, final int NUM_TESTS, String testName) {
try {
DecimalFormat df = new DecimalFormat("#.####");
long total = 0, start;
for (int i=0; i < NUM_TESTS; ++i) {
CloneableTestInput input = formInput.call();
CloneableTestInput orig_input = input.clone();
start = System.nanoTime();
outputType algorithmResult = runAlgorithm.apply(input);
total += System.nanoTime() - start;
outputType expectedResult = getKnownOutput.apply(orig_input);
assert(checkResults.apply(algorithmResult, expectedResult));
}
System.out.println("DEBUG: " + testName + " took "
+ df.format(total * 1.0 / NUM_TESTS)
+ " nanoseconds on average for " + NUM_TESTS + " tests");
} catch (Exception|AssertionError e) {
System.out.println(e.toString() + " - " + e.getMessage() + " - ");
e.printStackTrace();
}
}
}
/**
* Problem 6.2 from EPI
* Given an array A of digits encodiing a decimal number D,
* with MSD at A[0]. Update A to hold D + 1.
*/
public class PlusOne {
private static final int NUM_TESTS = (int) Math.pow(10, 5);
private static final int ARR_LENGTH = (int) Math.pow(10, 2);
private static ArrayList<Integer> plusOne(ArrayList<Integer> A) {
int n = A.size() - 1;
A.set(n, A.get(n) + 1);
for (int i = n; i > 0 && A.get(i) == 10; --i) {
A.set(i, 0);
A.set(i-1, A.get(i-1) + 1);
}
if (A.get(0) == 10) {
// Need additional digit up front as MSD
A.set(0,0);
A.add(0,1);
}
return A;
}
private static ArrayList<Integer> randArray(int len) {
ArrayList<Integer> A = new ArrayList<>();
if (len == 0) return A;
Random rgen = new Random();
A.add(rgen.nextInt(9) + 1);
--len;
while (len != 0) {
A.add(rgen.nextInt(10));
--len;
}
return A;
}
public static void main(String[] args) {
Callable<CloneableTestInput> formInput = () -> new CloneableArrayList(randArray(ARR_LENGTH));
Function<CloneableTestInput, ArrayList<Integer>> runAlgorithm =
(input) -> plusOne((ArrayList<Integer>) input);
Function<CloneableTestInput, ArrayList<Integer>> getKnownOutput =
(orig_input) -> {
BigInteger B = new BigInteger(Joiner.on("").join((ArrayList<Integer>) orig_input));
B = B.add(BigInteger.valueOf(1));
ArrayList<Integer> expectedOutput = new ArrayList<>();
while (B.compareTo(BigInteger.valueOf(0)) > 0) {
expectedOutput.add(0, B.mod(BigInteger.valueOf(10)).intValue());
B = B.divide(BigInteger.valueOf(10));
}
return expectedOutput;
};
BiFunction<ArrayList<Integer>, ArrayList<Integer>, Boolean> checkResults = List::equals;
TimeTests<ArrayList<Integer>> algTimer = new TimeTests<>();
algTimer.test(formInput, runAlgorithm, getKnownOutput, checkResults, NUM_TESTS, "PlusOne");
}
}
public class CanStringBePalindrome {
private static final int INPUT_STRING_LENGTH = (int) Math.pow(10, 2);
private static final int NUM_TESTS = (int) Math.pow(10, 6);
private static boolean canFormPalindromeHash(final String s) {
Map<Character, Integer> charFreqs = new HashMap<>();
for (int i = 0; i < s.length(); ++i) {
char c = s.charAt(i);
if (!charFreqs.containsKey(c))
charFreqs.put(c, 1);
else
charFreqs.put(c, charFreqs.get(c) + 1);
}
int oddFreqCount = 0;
for (Map.Entry<Character, Integer> entry : charFreqs.entrySet()) {
if ((entry.getValue() % 2) != 0 && (++oddFreqCount > 1))
return false;
}
return true;
}
private static boolean canFormPalindromeSorting(final String s) {
// TODO : find faster/simpler way of getting frequency counts
char[] a = s.toCharArray();
Arrays.sort(a);
int oddFreqCount = 0;
int numCurrChar =1;
for (int i = 1; i < a.length && oddFreqCount <= 1; ++i) {
if(a[i] != a[i-1]) {
if ((numCurrChar & 1) != 0)
++oddFreqCount;
numCurrChar = 1;
} else
++numCurrChar;
}
if ((numCurrChar & 1) != 0)
++oddFreqCount;
return oddFreqCount <= 1;
}
private static String randString(int len) {
StringBuilder sb = new StringBuilder();
Random rgen = new Random();
while (len-- > 0)
sb.append((char)(rgen.nextInt(26) + 'A'));
return sb.toString();
}
public static void main(String[] args) {
Callable<CloneableTestInput> formInput = () -> new CloneableString(randString(INPUT_STRING_LENGTH));
Function<CloneableTestInput, Boolean > runAlgorithm =
(input) -> canFormPalindromeHash(((CloneableString)input).data);
Function<CloneableTestInput, Boolean> getKnownOutput =
(orig_input) -> canFormPalindromeSorting(((CloneableString)orig_input).data);
BiFunction<Boolean, Boolean, Boolean> checkResults = Boolean::equals;
TimeTests<Boolean> algTimer = new TimeTests<>();
algTimer.test(formInput, runAlgorithm, getKnownOutput, checkResults
, NUM_TESTS, "CanStringBePalindrome");
}
}