Java 有缺陷的2-opt搜索实现？

我试图在Java中为TSP设计一个2-opt局部搜索启发式算法，但我的算法似乎有缺陷。给定最近邻电路作为输入，它会使电路变得更糟。最近邻居：；经过10秒的2-opt:。我的代码如下。我的实现有什么问题？Location[]Location只是图中节点的列表，每个节点都有纬度和经度以及它和另一个节点之间的距离计算

    public HamiltonianCircuit execute(Location[] locations) {
    long startTime = System.currentTimeMillis();
    while (true) {
        for (int i = 0; i < locations.length; i++) {
            for (int k = 0; k < locations.length; k++) {
                if (System.currentTimeMillis() - startTime >= 10000) {
                    return new HamiltonianCircuit(locations);
                }
                Location a = locations[i];
                Location b = locations[(i + 1) % locations.length];
                Location c = locations[k];
                Location d = locations[(k + 1) % locations.length];
                double distanceab = a.distanceBetween(b);
                double distancecd = c.distanceBetween(d);
                double distanceac = a.distanceBetween(c);
                double distancebd = b.distanceBetween(d);
                double change = (distanceab + distancecd) - 
                    (distanceac + distancebd);
                if (change > 0) {
                    locations[k] = a;
                    locations[i] = c;
                }
            }
        }
    }
}

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2-opt用边AC和BD替换边AB和CD，这意味着如果我们有部分电路0abxyzcd1开始，我们完成后需要0aczyxbd1。 您的代码将生成0cbxyzad1

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您想交换B和C，但也需要在中间反转所有的东西。

< P> java中可能的解决方案可能是：注意：VBOOSE < /P>

public HamiltonianCircuit execute(){
ArrayList<Vehicle> locations= new ArrayList<Locations>;
//populate array

    for (int i = 1; i < locations.size()-3; i++) {
            Location a = locations.get(i);
            Location b = locations.get(i+1);
            Location c = locations.get(i+2);
            Location d = locations.get(i+3);

            double distanceab = EuclidianDistance.pair(a, b);
            double distancebd = EuclidianDistance.pair(b, d);
            double distanceac = EuclidianDistance.pair(a, c);
            double distancecd = EuclidianDistance.pair(c, d);
            double abcd = distanceab+distancecd;
            double acbd = distanceac+distancebd;

            if(acbd<abcd){
                Collections.swap(locations, i+1, i+2);
                System.out.println("swapped"+vehicles);
            }
    }
    Locations.setDistance(EuclidianDistance.Collection(locations));
    return locations;
}