ó ,µ[c@s5dZddlZdgZdefd„ƒYZdS(s0Priority queue class with updatable priorities. iÿÿÿÿNt MappedQueuecBsbeZdZgd„Zd„Zd„Zd„Zd„Zd„Zd„Z d„Z d „Z RS( sÂThe MappedQueue class implements an efficient minimum heap. The smallest element can be popped in O(1) time, new elements can be pushed in O(log n) time, and any element can be removed or updated in O(log n) time. The queue cannot contain duplicate elements and an attempt to push an element already in the queue will have no effect. MappedQueue complements the heapq package from the python standard library. While MappedQueue is designed for maximum compatibility with heapq, it has slightly different functionality. Examples -------- A `MappedQueue` can be created empty or optionally given an array of initial elements. Calling `push()` will add an element and calling `pop()` will remove and return the smallest element. >>> q = MappedQueue([916, 50, 4609, 493, 237]) >>> q.push(1310) True >>> x = [q.pop() for i in range(len(q.h))] >>> x [50, 237, 493, 916, 1310, 4609] Elements can also be updated or removed from anywhere in the queue. >>> q = MappedQueue([916, 50, 4609, 493, 237]) >>> q.remove(493) >>> q.update(237, 1117) >>> x = [q.pop() for i in range(len(q.h))] >>> x [50, 916, 1117, 4609] References ---------- .. [1] Cormen, T. H., Leiserson, C. E., Rivest, R. L., & Stein, C. (2001). Introduction to algorithms second edition. .. [2] Knuth, D. E. (1997). The art of computer programming (Vol. 3). Pearson Education. cCs)t|ƒ|_tƒ|_|jƒdS(s8Priority queue class with updatable priorities. N(tlistthtdicttdt_heapify(tselftdata((s:lib/python2.7/site-packages/networkx/utils/mapped_queue.pyt__init__As cCs t|jƒS(N(tlenR(R((s:lib/python2.7/site-packages/networkx/utils/mapped_queue.pyt__len__HscCsxtj|jƒtgt|jƒD]\}}||f^q#ƒ|_t|jƒt|jƒkrttdƒ‚ndS(s+Restore heap invariant and recalculate map.s Heap contains duplicate elementsN(theapqtheapifyRRt enumerateRR tAssertionError(Rtpostelt((s:lib/python2.7/site-packages/networkx/utils/mapped_queue.pyRKs7cCsP||jkrtSt|jƒ}|jj|ƒ||j|<|j|ƒtS(sAdd an element to the queue.(RtFalseR Rtappendt _siftdowntTrue(RRR((s:lib/python2.7/site-packages/networkx/utils/mapped_queue.pytpushRs  cCs†|jd}|j|=t|jƒdkr=|jjƒ|S|jjƒ}||jdd}x||krA||}y•|d}||} | |kr­| |||<||<||}}||||<|| d}q:W|S(sUMove element at pos down to a leaf by repeatedly moving the smaller child up.i(RRR t IndexError( RRRRRtend_postleft_postleftt right_postright((s:lib/python2.7/site-packages/networkx/utils/mapped_queue.pyR’s,          cCs’|j|j}}||}xn|dkr|dd?}||}||kr‰||||<||<||}}|||<|||s