我想做点什么
array ((0,0), (25, 25)) [((i,j), 1) | i <- [0..25], j <- [i..25]]
仅在i <= j时定义。但是，当我尝试在ghci中打印出来时，我收到一个错误，因为它会因为数组边界而尝试打印(1,0)之类的内容。
((1,0),*** Exception: (Array.!): undefined array element
我可以让数组为正方形，并在这些条目中添加类似0的东西，但我认为这不是最理想的。有没有办法可以将这个数组的边界设置为“三角形”？
答案 0 :(得分：7)
一个简单的上三角索引可以定义为：
plugins {
compile ":spring-security-core:1.2.7.3"
}
即使数组不平方，也可以验证package applevel
import grails.test.*
import org.junit.*
import org.springframework.web.context.request.RequestContextHolder
import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.*;
import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestBuilders.*;
import static org.springframework.security.test.web.servlet.result.SecurityMockMvcResultMatchers.*;
import org.springframework.security.test.context.annotation.SecurityTestExecutionListeners;
import org.springframework.security.test.context.support.*;
@RunWith(SpringJUnit4ClassRunner.class)// unable to resolve
@ContextConfiguration //unable to resolve
@WebAppConfiguration //unable to resolve
class ReportControllerTests extends GroovyTestCase{
def springSecurityService
private WebApplicationContext context;
private MockMvc mvc; //unable to resolve MockMvc
@Before
void setUp() {
// Setup logic here
mvc = MockMvcBuilders
.webAppContextSetup(context)
.apply(springSecurity()) 1
.build();
}
@After
void tearDown() {
// Tear down logic here
}
@Test
//@WithMockUser(username="testAdmin", roles={"ADMIN"})->unable to resolve
void testIndex() {
mvc.perform(get("/report").with(user("testAdmin").password("_testpass_").roles("ADMIN")))
}
和import Data.Ix (Ix, range, index, inRange)
data UpperTriagIndex = Int :. Int
deriving (Show, Ord, Eq)
instance Ix UpperTriagIndex where
range (a :. b, c :. d) = concatMap (\i -> (i :.) <$> [max i b..d]) [a..c]
inRange (a :. b, c :. d) (i :. j) = a <= i && i <= c && b <= j && j <= d
index pr@(a :. b, c :. d) ix@(i :. j)
| inRange pr ix = f a - f i + j - i
| otherwise = error "out of range!"
where f x = let s = d + 1 - max x b in s * (s + 1) `div` 2
往返。例如：
range和
index