Tidy up the whole NSArray+EKStuff

- Add some tests
- Correct counts "To optimize each loop." (#49)
- Other minor cleanups

EKAlgorithms/NSArray+EKStuff.h

@@ -49,8 +49,8 @@
  */
 - (NSNumber *)sumOfElements;
 
+- (NSDictionary *)occurencesOfEachElementInArray_naive;
 - (NSDictionary *)occurencesOfEachElementInArray;
-- (NSDictionary *)occurencesOfEachElementInArrayByUsingDictionary;
 - (NSDictionary *)CocoaImplementationOfOccurencesOfEachElementInArray;
 
 //search

EKAlgorithms/NSArray+EKStuff.m

@@ -7,7 +7,6 @@
 //
 
 #import "NSArray+EKStuff.h"
-#import "NSMutableArray+EKStuff.h"
 
 @implementation NSArray (EKStuff);
 
@@ -18,8 +17,10 @@ - (NSUInteger)indexOfMaximumElement
 {
     NSInteger maximumValue = [[self objectAtIndex:0] integerValue];
     NSUInteger indexOfMaximumValue = 0;
-
-    for (NSUInteger i = 1; i < [self count]; i++) {
+
+    NSUInteger count = [self count];
+
+    for (NSUInteger i = 1; i < count; i++) {
         NSInteger value = [[self objectAtIndex:i] integerValue];
 
         if (value > maximumValue) {
@@ -114,7 +115,7 @@ - (NSString *)longestString
     NSString *returnValue = nil;
 
     for (NSString *string in self) {
-        if (returnValue == nil || [string length] > [returnValue length]) {
+        if (returnValue == nil || ([string length] > [returnValue length])) {
             returnValue = string;
         }
     }
@@ -129,7 +130,7 @@ - (NSString *)shortestString
     NSString *returnValue = nil;
 
     for (NSString *string in self) {
-        if (returnValue == nil || [string length] < [returnValue length]) {
+        if (returnValue == nil || ([string length] < [returnValue length])) {
             returnValue = string;
         }
     }
@@ -143,7 +144,7 @@ - (NSArray *)intersectionWithArray:(NSArray *)secondArray
 {
     NSMutableSet *intersection = [NSMutableSet setWithArray:self];
     [intersection intersectSet:[NSSet setWithArray:secondArray]];
-    
+
     return [intersection allObjects];
 }
 
@@ -203,9 +204,11 @@ + (NSArray *)randomObjectsWithArraySize:(NSUInteger)arraySize maxRandomValue:(NS
 
 - (NSNumber *)sumOfElements
 {
+    NSUInteger count = [self count];
+
     long long int sum = 0;
 
-    for (NSUInteger i = 0; i < [self count]; i++) {
+    for (NSUInteger i = 0; i < count; i++) {
         sum = sum + [self[i] longLongValue];
     }
 
@@ -214,45 +217,47 @@ - (NSNumber *)sumOfElements
 
 #pragma mark - Occurrences of each element in array
 
-- (NSDictionary *)occurencesOfEachElementInArray
+- (NSDictionary *)occurencesOfEachElementInArray_naive
 {
-    NSMutableDictionary *result = [@{} mutableCopy];
-
-    for (NSUInteger i = 0; i < [self count]; i++) {
-        NSParameterAssert(self[i] != nil);
+    NSUInteger count = [self count];
+
+    NSMutableDictionary *registry = [NSMutableDictionary dictionaryWithCapacity:count];
+
+    for (NSUInteger i = 0; i < count; i++) {
         NSUInteger counter = 0;
-        for (NSUInteger j = 0; j < [self count]; j++) {
-            NSParameterAssert(self[j] != nil);
+
+        for (NSUInteger j = 0; j < count; j++) {
             if ([self[i] isEqual:self[j]]) {
                 counter++;
             }
         }
-        [result setObject:[NSNumber numberWithUnsignedInteger:counter]
+
+        [registry setObject:@(counter)
                    forKey:self[i]];
     }
 
-    return result;
+    return registry;
 }
 
-- (NSDictionary *)occurencesOfEachElementInArrayByUsingDictionary
+- (NSDictionary *)occurencesOfEachElementInArray
 {
-    NSMutableDictionary *result = [@{} mutableCopy];
-
-    for (NSUInteger i = 0; i < [self count]; i++) {
+    NSUInteger count = [self count];
+
+    NSMutableDictionary *registry = [NSMutableDictionary dictionaryWithCapacity:count];
+
+    for (NSUInteger i = 0; i < count; i++) {
         id currentElement = self[i];
-
-        NSParameterAssert(currentElement != nil);
-
-        NSNumber *existingElementCounter = result[currentElement];
+
+        NSNumber *existingElementCounter = registry[currentElement];
 
         NSUInteger currentCount = existingElementCounter ? existingElementCounter.unsignedIntegerValue : 0;
 
         currentCount++;
 
-        result[currentElement] = [NSNumber numberWithUnsignedInteger:currentCount];
+        registry[currentElement] = @(currentCount);
     }
 
-    return result;
+    return registry;
 }
 
 - (NSDictionary *)CocoaImplementationOfOccurencesOfEachElementInArray
@@ -261,7 +266,6 @@ - (NSDictionary *)CocoaImplementationOfOccurencesOfEachElementInArray
     NSMutableDictionary *dictionary = [@{} mutableCopy];
 
     for (id object in [countedSet allObjects]) {
-        NSParameterAssert(object != nil);
         [dictionary setObject:@([countedSet countForObject:object])
                        forKey:object];
     }
@@ -274,19 +278,15 @@ - (NSDictionary *)CocoaImplementationOfOccurencesOfEachElementInArray
 
 - (NSInteger)indexOfObjectViaLinearSearch:(id)object
 {
-    NSInteger i = 0, indexOfFoundedObject = 0;
-
-    for (i = 0; i < [self count]; i++) {
-        if (object == [self objectAtIndex:i]) {
-            indexOfFoundedObject = i;
-            break;
+    NSUInteger count = [self count];
+
+    for (int i = 0; i < count; i++) {
+        if ([object isEqual:[self objectAtIndex:i]]) {
+            return i;
         }
     }
-    if (i == [self count]) {
-        indexOfFoundedObject = -1;
-    }
-
-    return indexOfFoundedObject;
+
+    return NSNotFound;
 }
 
 #pragma mark - Binary search
@@ -295,24 +295,22 @@ - (NSInteger)indexOfObjectViaBinarySearch:(id)object
 {
     NSUInteger firstIndex = 0;
     NSUInteger uptoIndex = [self count];
-    NSUInteger indexOfFoundedObject = 0;
-
+
     while (firstIndex < uptoIndex) {
         NSUInteger mid = (firstIndex + uptoIndex) / 2;
-        if ([object isKindOfClass:[NSNumber class]]) {
-            if ([object integerValue] < [[self objectAtIndex:mid] integerValue]) {
-                uptoIndex = mid;
-            }
-            else if ([object integerValue] > [[self objectAtIndex:mid] integerValue]) {
-                firstIndex = mid + 1;
-            }
-            else {
-                return indexOfFoundedObject = mid;
-            }
+
+        if ([object integerValue] < [[self objectAtIndex:mid] integerValue]) {
+            uptoIndex = mid;
+        }
+        else if ([object integerValue] > [[self objectAtIndex:mid] integerValue]) {
+            firstIndex = mid + 1;
+        }
+        else {
+            return mid;
         }
     }
 
-    return indexOfFoundedObject = -1;
+    return NSNotFound;
 }
 
 

EKAlgorithmsApp/EKAlgorithmsApp.xcodeproj/project.pbxproj

@@ -25,12 +25,10 @@
 		860B78821858133A0071079A /* EKLinkedList.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78701858133A0071079A /* EKLinkedList.m */; };
 		860B78831858133A0071079A /* EKNode.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78721858133A0071079A /* EKNode.m */; };
 		860B78841858133A0071079A /* NSArray+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78741858133A0071079A /* NSArray+EKStuff.m */; };
-		860B78851858133A0071079A /* NSMutableArray+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78761858133A0071079A /* NSMutableArray+EKStuff.m */; };
 		860B78861858133A0071079A /* NSNumber+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78781858133A0071079A /* NSNumber+EKStuff.m */; };
 		860B78871858133A0071079A /* NSString+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B787A1858133A0071079A /* NSString+EKStuff.m */; };
 		860B7889185814810071079A /* NSArray.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B7888185814810071079A /* NSArray.m */; };
 		860B788A185815BC0071079A /* NSArray+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78741858133A0071079A /* NSArray+EKStuff.m */; };
-		8641D23F18C88D6700B109E4 /* NSMutableArray+EKStuff.m in Sources */ = {isa = PBXBuildFile; fileRef = 860B78761858133A0071079A /* NSMutableArray+EKStuff.m */; };
 		8641D24618C89B7100B109E4 /* NSArray+Selection.m in Sources */ = {isa = PBXBuildFile; fileRef = 8641D24518C89B7100B109E4 /* NSArray+Selection.m */; };
 		8641D24718C89BC900B109E4 /* NSArray+Selection.m in Sources */ = {isa = PBXBuildFile; fileRef = 8641D24518C89B7100B109E4 /* NSArray+Selection.m */; };
 		8692312418E983A2002F7CBA /* NSArray+EKSorting.m in Sources */ = {isa = PBXBuildFile; fileRef = 86A39FCE18E97F3300124215 /* NSArray+EKSorting.m */; };
@@ -116,8 +114,6 @@
 		860B78721858133A0071079A /* EKNode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = EKNode.m; sourceTree = "<group>"; };
 		860B78731858133A0071079A /* NSArray+EKStuff.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSArray+EKStuff.h"; sourceTree = "<group>"; };
 		860B78741858133A0071079A /* NSArray+EKStuff.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSArray+EKStuff.m"; sourceTree = "<group>"; };
-		860B78751858133A0071079A /* NSMutableArray+EKStuff.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSMutableArray+EKStuff.h"; sourceTree = "<group>"; };
-		860B78761858133A0071079A /* NSMutableArray+EKStuff.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSMutableArray+EKStuff.m"; sourceTree = "<group>"; };
 		860B78771858133A0071079A /* NSNumber+EKStuff.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSNumber+EKStuff.h"; sourceTree = "<group>"; };
 		860B78781858133A0071079A /* NSNumber+EKStuff.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSNumber+EKStuff.m"; sourceTree = "<group>"; };
 		860B78791858133A0071079A /* NSString+EKStuff.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSString+EKStuff.h"; sourceTree = "<group>"; };
@@ -264,8 +260,6 @@
 				860B785B1858133A0071079A /* Data Structures */,
 				860B78731858133A0071079A /* NSArray+EKStuff.h */,
 				860B78741858133A0071079A /* NSArray+EKStuff.m */,
-				860B78751858133A0071079A /* NSMutableArray+EKStuff.h */,
-				860B78761858133A0071079A /* NSMutableArray+EKStuff.m */,
 				860B78771858133A0071079A /* NSNumber+EKStuff.h */,
 				860B78781858133A0071079A /* NSNumber+EKStuff.m */,
 				860B78791858133A0071079A /* NSString+EKStuff.h */,
@@ -502,7 +496,6 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				860B78851858133A0071079A /* NSMutableArray+EKStuff.m in Sources */,
 				860B787D1858133A0071079A /* EKDeque.m in Sources */,
 				8FF772EF18E6E24300DF6B3A /* EKAVLTree.m in Sources */,
 				8F8F83FE18E75E5A0009D125 /* EKBHeap.m in Sources */,
@@ -545,7 +538,6 @@
 				86A2D37C188D2705004A908F /* NSArray+EKGeometry.m in Sources */,
 				8F8F83FF18E75E5A0009D125 /* EKBHeap.m in Sources */,
 				86A2D378188D2440004A908F /* EKGeometry.m in Sources */,
-				8641D23F18C88D6700B109E4 /* NSMutableArray+EKStuff.m in Sources */,
 				860B7850185811420071079A /* main.m in Sources */,
 				869FE65F186419E600509FE7 /* NSNumber.m in Sources */,
 				8FF772F418E6E53F00DF6B3A /* EKAVLTreeNode.m in Sources */,

EKAlgorithmsSpecs/NSArray.m

@@ -1,7 +1,6 @@
 #import <Kiwi/Kiwi.h>
 
 #import "NSArray+EKStuff.h"
-#import "NSMutableArray+EKStuff.h"
 #import "NSArray+Selection.h"
 #import "NSArray+EKSorting.h"
 
@@ -245,7 +244,7 @@
     });
 
     describe(@"Occurrences of each element in array", ^{
-        describe(@"occurencesOfEachElementInArray", ^{
+        describe(@"occurencesOfEachElementInArray_naive", ^{
             specify(^{
                 NSMutableArray *originalArray = [NSMutableArray array];
 
@@ -258,6 +257,27 @@
                     }
                 }
 
+                NSDictionary *result = [originalArray occurencesOfEachElementInArray_naive];
+
+                for (int i = 1; i <= N; i++) {
+                    [[result[@(i)] should] equal:@(i)];
+                }
+            });
+        });
+
+        describe(@"occurencesOfEachElementInArray", ^{
+            specify(^{
+                NSMutableArray *originalArray = [NSMutableArray array];
+
+                // Just the array to test the method against
+                // [@(1), @(2), @(2), @(3), @(3), @(3), ...]
+                int N = 100;
+                for (int i = 1; i <= N; i++) {
+                    for (int j = 1; j <= i; j++) {
+                        [originalArray addObject:@(i)];
+                    }
+                }
+
                 NSDictionary *result = [originalArray occurencesOfEachElementInArray];
 
                 for (int i = 1; i <= N; i++) {
@@ -266,26 +286,27 @@
             });
         });
 
-        describe(@"occurencesOfEachElementInArrayByUsingDictionary", ^{
+        describe(@"CocoaImplementationOfOccurencesOfEachElementInArray", ^{
             specify(^{
                 NSMutableArray *originalArray = [NSMutableArray array];
 
                 // Just the array to test the method against
                 // [@(1), @(2), @(2), @(3), @(3), @(3), ...]
-                int N = 10;
+                int N = 100;
                 for (int i = 1; i <= N; i++) {
                     for (int j = 1; j <= i; j++) {
                         [originalArray addObject:@(i)];
                     }
                 }
 
-                NSDictionary *result = [originalArray occurencesOfEachElementInArrayByUsingDictionary];
+                NSDictionary *result = [originalArray CocoaImplementationOfOccurencesOfEachElementInArray];
 
                 for (int i = 1; i <= N; i++) {
                     [[result[@(i)] should] equal:@(i)];
                 }
             });
         });
+
     });
 
     describe(@"Selection algorithms", ^{