3 d*@sldZddlmZmZddlmZddlZdddgZGdddZ d d Z Gd dde Z Gd dde Z dS) z Min-heaps. )heappopheappush)countNMinHeap PairingHeap BinaryHeapc@sjeZdZdZGdddZddZddZdd Zdd d ZdddZ ddZ ddZ ddZ ddZ d S)rzBase class for min-heaps. A MinHeap stores a collection of key-value pairs ordered by their values. It supports querying the minimum pair, inserting a new pair, decreasing the value in an existing pair and deleting the minimum pair. c@s$eZdZdZd ZddZddZdS) z MinHeap._Itemz;Used by subclassess to represent a key-value pair. keyvaluecCs||_||_dS)N)rr )selfrr r 8/tmp/pip-build-7vycvbft/networkx/networkx/utils/heaps.py__init__szMinHeap._Item.__init__cCst|j|jfS)N)reprrr )r r r r __repr__szMinHeap._Item.__repr__N)rr )__name__ __module__ __qualname____doc__ __slots__r rr r r r _ItemsrcCs i|_dS)z#Initialize a new min-heap. N)_dict)r r r r r !szMinHeap.__init__cCstdS)aQuery the minimum key-value pair. Returns ------- key, value : tuple The key-value pair with the minimum value in the heap. Raises ------ NetworkXError If the heap is empty. N)NotImplementedError)r r r r min&s z MinHeap.mincCstdS)aDelete the minimum pair in the heap. Returns ------- key, value : tuple The key-value pair with the minimum value in the heap. Raises ------ NetworkXError If the heap is empty. N)r)r r r r pop5s z MinHeap.popNcCstdS)aReturns the value associated with a key. Parameters ---------- key : hashable object The key to be looked up. default : object Default value to return if the key is not present in the heap. Default value: None. Returns ------- value : object. The value associated with the key. N)r)r rdefaultr r r getDsz MinHeap.getFcCstdS)a<Insert a new key-value pair or modify the value in an existing pair. Parameters ---------- key : hashable object The key. value : object comparable with existing values. The value. allow_increase : bool Whether the value is allowed to increase. If False, attempts to increase an existing value have no effect. Default value: False. Returns ------- decreased : bool True if a pair is inserted or the existing value is decreased. N)r)r rr allow_increaser r r insertWszMinHeap.insertcCs t|jS)z+Returns whether the heap if empty. )boolr)r r r r __nonzero__nszMinHeap.__nonzero__cCs t|jS)z+Returns whether the heap if empty. )rr)r r r r __bool__sszMinHeap.__bool__cCs t|jS)z;Returns the number of key-value pairs in the heap. )lenr)r r r r __len__xszMinHeap.__len__cCs ||jkS)zReturns whether a key exists in the heap. Parameters ---------- key : any hashable object. The key to be looked up. )r)r rr r r __contains__}szMinHeap.__contains__)N)F)rrrrrr rrrrrr r"r#r r r r r s   csfdd}|S)z;Decorator for inheriting docstrings from base classes. csj|jj|_|S)N)__dict__rr)fn)clsr r funcsz_inherit_doc..funcr )r&r'r )r&r _inherit_docs r(cseZdZdZGdddejZfddZeeddZ eedd Z eedd d Z eedddZ ddZ ddZddZZS)rzA pairing heap. cs$eZdZdZdZfddZZS) zPairingHeap._NodezA node in a pairing heap. A tree in a pairing heap is stored using the left-child, right-sibling representation. leftnextprevparentcs0ttj|j||d|_d|_d|_d|_dS)N)superr_Noder r)r*r+r,)r rr ) __class__r r r s zPairingHeap._Node.__init__)r)r*r+r,)rrrrrr __classcell__r r )r/r r.sr.cstjd|_dS)z#Initialize a pairing heap. N)r-r _root)r )r/r r r s zPairingHeap.__init__cCs$|jdkrtjd|jj|jjfS)Nzheap is empty.)r1nx NetworkXErrorrr )r r r r rs  zPairingHeap.mincCs>|jdkrtjd|j}|j|j|_|j|j=|j|jfS)Nzheap is empty.)r1r2r3_merge_childrenrrr )r Zmin_noder r r rs    zPairingHeap.popNcCs|jj|}|dk r|jS|S)N)rrr )r rrnoder r r rs zPairingHeap.getFcCs|jj|}|j}|dk r||jkrZ||_||k rV||jjkrV|j||j|||_dS|r||jkr||_|j|}|dk r|j|j||_dS|j||}||j|<|dk r|j||n||_dSdS)NTF) rrr1r r,_cut_linkr4r.)r rr rr5rootchildr r r rs&       zPairingHeap.insertcCsF|j|jkr||}}|j}||_|dk r0||_d|_||_||_|S)z_Link two nodes, making the one with the smaller value the parent of the other. N)r r)r*r+r,)r r8otherr*r r r r7s  zPairingHeap._linkcCs|j}d|_|dk r|j}d}xB|j}|dkr6||_P|j}|||}||_|}|dkrZP|}q W|j}x |dk r|j}|||}|}qjWd|_d|_d|_|S)zMerge the subtrees of the root using the standard two-pass method. The resulting subtree is detached from the root. N)r)r7r*r+r,)r r8r5linkr+r*Z next_nextZ prev_prevr r r r4s4   zPairingHeap._merge_childrencCsH|j}|j}|dk r||_n||j_d|_|dk r>||_d|_d|_dS)z$Cut a node from its parent. N)r+r*r,r))r r5r+r*r r r r6szPairingHeap._cut)N)F)rrrrrrr.r r(rrrrr7r4r6r0r r )r/r rs    $&csdeZdZdZfddZeeddZeeddZeedd d Z eedd d Z Z S)rzA binary heap. cstjg|_t|_dS)z"Initialize a binary heap. N)r-r _heapr_count)r )r/r r r 3s zBinaryHeap.__init__cCsX|j}|stjd|j}t}x0|d\}}}||krD|||krDP||q W||fS)Nz heap is emptyr)rr2r3r<r)r dictheaprr _rr r r r:s  zBinaryHeap.mincCs^|j}|stjd|j}t}x0|d\}}}||||kr |||kr Pq W||=||fS)Nz heap is emptyr)rr2r3r<r)r r>r?rr r@rr r r rJs zBinaryHeap.popNcCs|jj||S)N)rr)r rrr r r r[szBinaryHeap.getFcCs~|j}||krV||}||ks*|rR||krR|||<t|j|t|j|f||kSdS|||<t|j|t|j|fdSdS)NFT)rrr<r*r=)r rr rr> old_valuer r r r_szBinaryHeap.insert)N)F) rrrrr r(rrrrrr0r r )r/r r/s  ) rheapqrr itertoolsrZnetworkxr2__all__rr(rrr r r r s  |