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Objective-C??BFS??????????????

Objective-C??????????????????iOS?macOS??????????????????Objective-C????????????BFS??????????????????????????????????????????????????????????Objective-C???BFS???

BFS???????????????????????????????????DFS????BFS????????????????????????????????????????

BFS????

Objective-C????

?????BFS?????Objective-C?????

#import 
   
    #import "Graph.h"@interface Graph : NSObject@property (nonatomic, assign) NSInteger nodeCount;@property (nonatomic, strong) NSMutableDictionary * adjacencyList;@end@implementation Graph- (void) initializeGraphWithNodes:(NSInteger)nodeCount {    self.nodeCount = nodeCount;    self.adjacencyList = [NSMutableDictionary new];    for (NSInteger i = 0; i < nodeCount; i++) {        [self.adjacencyList setValue:[NSMutableArray new] forKey:[NSString stringWithFormat:@"%d", i]];    }}- (void) addEdgeBetweenNodes:(NSInteger)from to:(NSInteger)to {    [[self.adjacencyList valueForKey:[NSString stringWithFormat:@"%d", from]] addObject:to];    [[self.adjacencyList valueForKey:[NSString stringWithFormat:@"%d", to]] addObject:from];}- (NSArray *) shortestPathFrom:(NSInteger)start to:(NSInteger)end {    if (start == end) {        return [NSArray arrayWithObject:@-1];    }        BOOL *visited = [malloc sizeof(BOOL) * self.nodeCount];    visited[start] = true;    NSInteger *distance = [malloc sizeof(NSInteger) * self.nodeCount];    distance[start] = 0;        NSMutableArray *queue = [NSMutableArray new];    [queue addObject:start];        while (!queue.isEmpty) {        NSInteger current = [queue.firstObject integerValue];        NSInteger currentIndex = current;                for (NSInteger neighbor in [self.adjacencyList valueForKey:[NSString stringWithFormat:@"%d", currentIndex]]) {            if (!visited[neighbor]) {                visited[neighbor] = true;                distance[neighbor] = distance[currentIndex] + 1;                [queue addObject:neighbor];            }        }                [queue removeObjectAtIndex:0];    }        if (!visited[end]) {        return nil;    }        NSInteger current = end;    NSMutableArray *path = [NSMutableArray new];    while (current != start) {        [path addObject:[NSString stringWithFormat:@"%d", current]];        current = [distance objectAtIndex:current];    }        [path reverse];    return path;}@end
   

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BFS?????????????????????????????????2D????????????????????BFS??????????????????????

??

• ??????O(V + E)???V?????E????
• ??????O(V + E)?
• ???????????????????

BFS????????????????????????????????Objective-C???????????

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