a J5d @sdZddlmZddlmZddlmZmZmZddl Z ddl m Z ddl mZde jeeeeeeeeeeeefd d d Zde jeeeeeefd ddZdS)zSimple local search solver)sample) default_timer)ListOptionalTupleN)compute_permutation_distance)neighborhood_gentwo_optF)distance_matrixx0perturbation_schememax_processing_timelog_fileverbosereturncCst||\}}|ptj}|r*t|ddd}t} d} d} | r| sd} tt||D]\} } t| |krd}|r~t||d|rt|d} q8t|| }d|d | }|rt||d|rt|||krTd} | |}}q8qTq8||fS) aSolve a TSP problem with a local search heuristic Parameters ---------- distance_matrix Distance matrix of shape (n x n) with the (i, j) entry indicating the distance from node i to j x0 Initial permutation. If not provided, it starts with a random path perturbation_scheme {"ps1", "ps2", "ps3", "ps4", "ps5", "ps6", ["two_opt"]} Mechanism used to generate new solutions. Defaults to "two_opt" max_processing_time {None} Maximum processing time in seconds. If not provided, the method stops only when a local minimum is obtained log_file If not `None`, creates a log file with details about the whole execution verbose If true, prints algorithm status every iteration Returns ------- A permutation of nodes from 0 to n - 1 that produces the least total distance obtained (not necessarily optimal). The total distance the returned permutation produces. Notes ----- Here are the steps of the algorithm: 1. Let `x`, `fx` be a initial solution permutation and its objective value; 2. Perform a neighborhood search in `x`: 2.1 For each `x'` neighbor of `x`, if `fx'` < `fx`, set `x` <- `x'` and stop; 3. Repeat step 2 until all neighbors of `x` are tried and there is no improvement. Return `x`, `fx` as solution. wzutf-8)encodingFTz/WARNING: Stopping early due to time constraints)filezCurrent value: z ; Neighbor: ) setupnpinfopenr enumeraterprintr)r r r r rrxZfxZlog_file_handlerZticZ stop_earlyZ improvementZn_indexZxnZ warning_msgfnmsgr^/var/www/html/django/DPS/env/lib/python3.9/site-packages/python_tsp/heuristics/local_search.pysolve_tsp_local_search s:3     r)r r rcCs:|s(|jd}dgttd||d}t||}||fS)aReturn initial solution and its objective value Parameters ---------- distance_matrix Distance matrix of shape (n x n) with the (i, j) entry indicating the distance from node i to j x0 Permutation of nodes from 0 to n - 1 indicating the starting solution. If not provided, a random list is created. Returns ------- x0 Permutation with initial solution. If ``x0`` was provided, it is the same list fx0 Objective value of x0 r)shaperranger)r r nZfx0rrrrcs   r)Nr NNF)N)__doc__randomrZtimeitrtypingrrrnumpyrZpython_tsp.utilsrZ*python_tsp.heuristics.perturbation_schemesrZndarrayintstrfloatboolrrrrrrs2      X