U :v f(@sddZddlmZmZddlmZddlZdddgZGdddZ 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$eZdZdZdZddZddZdS)z MinHeap._Itemz2Used by subclassess to represent a key-value pair.keyvaluecCs||_||_dSNrselfr r r8/tmp/pip-unpacked-wheel-_lngutwb/networkx/utils/heaps.py__init__szMinHeap._Item.__init__cCst|j|jfSr )reprr r r rrr__repr__szMinHeap._Item.__repr__N)__name__ __module__ __qualname____doc__ __slots__rrrrrr_ItemsrcCs i|_dS)zInitialize a new min-heap.N_dictrrrrr!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. NNotImplementedErrorrrrrmin%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. Nrrrrrpop4s 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. Nrr r defaultrrrgetCsz 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. Nr)r r r allow_increaserrrinsertVszMinHeap.insertcCs t|jSz"Returns whether the heap if empty.boolrrrrr __nonzero__mszMinHeap.__nonzero__cCs t|jSr%r&rrrr__bool__qszMinHeap.__bool__cCs t|jS)z2Returns the number of key-value pairs in the heap.)lenrrrrr__len__uszMinHeap.__len__cCs ||jkS)zReturns whether a key exists in the heap. Parameters ---------- key : any hashable object. The key to be looked up. r)r r rrr __contains__yszMinHeap.__contains__)N)F)rrrrrrrrr"r$r(r)r+r,rrrrr s   csneZdZdZGdddejZfddZddZdd Z dd d Z dddZ ddZ ddZ ddZZS)rzA pairing heap.cs$eZdZdZdZfddZZS)zPairingHeap._NodezA node in a pairing heap. A tree in a pairing heap is stored using the left-child, right-sibling representation. )leftnextprevparentcs*t||d|_d|_d|_d|_dSr )superrr-r.r/r0r  __class__rrrs zPairingHeap._Node.__init__)rrrrrr __classcell__rrr2r_Nodesr5cstd|_dS)zInitialize a pairing heap.N)r1r_rootrr2rrrs zPairingHeap.__init__cCs$|jdkrtd|jj|jjfSNzheap is empty.)r6nx NetworkXErrorr r rrrrrs  zPairingHeap.mincCs>|jdkrtd|j}||j|_|j|j=|j|jfSr7)r6r8r9_merge_childrenrr r )r Zmin_noderrrrs    zPairingHeap.popNcCs|j|}|dk r|jS|Sr )rr"r )r r r!noderrrr"s zPairingHeap.getFcCs|j|}|j}|dk r||jkrZ||_||k rV||jjkrV||||||_dS|r||jkr||_||}|dk r||j||_dS|||}||j|<|dk r|||n||_dSdS)NTF) rr"r6r r0_cut_linkr:r5)r r r r#r;rootchildrrrr$s&       zPairingHeap.insertcCsF|j|jkr||}}|j}||_|dk r0||_d|_||_||_|S)z_Link two nodes, making the one with the smaller value the parent of the other. N)r r-r.r/r0)r r>otherr.rrrr=s  zPairingHeap._linkcCs|j}d|_|dk r|j}d}|j}|dkr4||_q^|j}|||}||_|}|dkrXq^|}q|j}|dk r|j}|||}|}qdd|_d|_d|_|S)zMerge the subtrees of the root using the standard two-pass method. The resulting subtree is detached from the root. N)r-r=r.r/r0)r r>r;linkr/r.Z next_nextZ prev_prevrrrr:s2  zPairingHeap._merge_childrencCsH|j}|j}|dk r||_n||j_d|_|dk r>||_d|_d|_dS)zCut a node from its parent.N)r/r.r0r-)r r;r/r.rrrr< szPairingHeap._cut)N)F)rrrrrrr5rrrr"r$r=r:r<r4rrr2rrs   $&csDeZdZdZfddZddZddZdd d Zdd d ZZ S)rzA binary heap.cstg|_t|_dS)zInitialize a binary heap.N)r1r_heapr_countrr2rrrs zBinaryHeap.__init__cCsT|j}|std|j}t}|d\}}}||krB|||krBqL||q||fSNz heap is emptyrrr8r9rBrr dictheaprr _r rrrr"s  zBinaryHeap.mincCsZ|j}|std|j}t}|d\}}}||||kr|||krqLq||=||fSrDrErFrrrr1s zBinaryHeap.popNcCs|j||Sr )rr"r rrrr"AszBinaryHeap.getFcCs~|j}||krV||}||ks*|rR||krR|||<t|j|t|j|f||kSdS|||<t|j|t|j|fdSdS)NFT)rrrBr.rC)r r r r#rG old_valuerrrr$DszBinaryHeap.insert)N)F) rrrrrrrr"r$r4rrr2rrs   ) rheapqrr itertoolsrZnetworkxr8__all__rrrrrrrs  w