Question

我试图弄清楚如何对10000个随机整数的数组进行排序并将其绘制成图形。从技术上讲，代码按升序排序，但在排序过程中的某个地方，它会将一堆值重置为相同。它看起来像一个阶梯函数，它应该只是一条连续的线。

 A;  
 for j = 1 : Nx-1    
     minvalue = A(j) ; 
     pointerminvalue = j ;
    for i = j : Nx        
        if (A(i) < minvalue )         
            minvalue = A(i)  ;         
            pointerminvalue = i ;     
        end
    end
    maxvalue = A(j) ;     
    A(j) = A(pointerminvalue) ;    
    A(pointerminvalue) = minvalue ;  
    % dont put the end here 
    A ;  
 end

知道我可能犯错的地方吗？

Answer 1

错误在于：

public class MapsActivity extends FragmentActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        setUpMapIfNeeded();
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    /**
     * Sets up the map if it is possible to do so (i.e., the Googlce Play services APK is corretly
     * installed) and the map has not already been instantiated.. This will ensure that we only ever
     * call {@link #setUpMap()} once when {@link #mMap} is not null.
     * <p/>
     * If it isn't installed {@link SupportMapFragment} (and
     * {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
     * install/update the Google Play services APK on their device.
     * <p/>
     * A user can return to this FragmentActivity after following the prompt and correctly
     * installing/updating/enabling the Google Play services. Since the FragmentActivity may not
     * have been completely destroyed during this process (it is likely that it would only be
     * stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
     * method in {@link #onResume()} to guarantee that it will be called.
     */
    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p/>
     * This should only be called once and when we are sure that {@link #mMap} is not null.
     */
    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker").snippet("Snippet"));

        // Enable MyLocation Layer of Google Map
        mMap.setMyLocationEnabled(false);

        // Get LocationManager object from System Service LOCATION_SERVICE
        LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // Create a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Get the name of the best provider
        String provider = locationManager.getBestProvider(criteria, true);

        // Get Current Location
        Location myLocation = locationManager.getLastKnownLocation(provider);

        // set map type
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        // Get latitude of the current location
        double latitude = myLocation.getLatitude();

        // Get longitude of the current location
        double longitude = myLocation.getLongitude();

        // Create a LatLng object for the current location
        LatLng latLng = new LatLng(latitude, longitude);

        // Show the current location in Google Map
        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        // Zoom in the Google Map
        mMap.animateCamera(CameraUpdateFactory.zoomTo(18));
        mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!").snippet("Consider yourself located"));
        mMap.getUiSettings().setAllGesturesEnabled(false);
    }
}

您正在使用两个不同的变量名称，将其更改为

maxvalue = A(j) ;     
A(j) = A(pointerminvalue) ;    
A(pointerminvalue) = minvalue ;

创建升序排序功能

1 个答案: