当数字反转为零时结束。输出中不打印零。例如：11120但输出= 2111。请查看附件图片 码： code i have written for reverse of the number
答案 0 :(得分：1)
几乎每种编程语言中的大多数整数类型都不显示前导零。如果要用零反转它，请先转换为字符串。如果你想要前导零，你需要指定你想要显示的位数。
内部11120存储为00000000000000000010101101110000，为了便于阅读，它只显示为11120。
答案 1 :(得分：0)
package com.zonal.regionview;
import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.os.Vibrator;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.RelativeLayout;
import java.util.HashMap;
import java.util.Map;
/**
* Created by Alexander Thomas (@Cawfree) on 20/07/2017.
*/
/** Enables users to customize Regions Of Interest on a Canvas. */
public class RegionView extends RelativeLayout implements View.OnTouchListener, GestureDetector.OnGestureListener, ScaleGestureDetector.OnScaleGestureListener {
/* Member Variables. */
private final GestureDetector mGestureDetector;
private final ScaleGestureDetector mScaleGestureDetector;
private final Map<Integer, View> mViewMap;
private boolean mScaling;
private float mScale;
private boolean mWrapContent;
private boolean mDropOnScale;
public RegionView(Context context) {
// Implement the Parent.
super(context);
// Initialize Member Variables.
this.mGestureDetector = new GestureDetector(context, this);
this.mViewMap = new HashMap<>();
this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
this.mScaling = false;
this.mScale = Float.NaN;
this.mWrapContent = false;
this.mDropOnScale = false;
// Register ourself as the OnTouchListener.
this.setOnTouchListener(this);
}
public RegionView(Context context, @Nullable AttributeSet attrs) {
// Implement the Parent.
super(context, attrs);
// Initialize Member Variables.
this.mGestureDetector = new GestureDetector(context, this);
this.mViewMap = new HashMap<>();
this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
this.mScaling = false;
this.mWrapContent = false;
this.mDropOnScale = false;
// Register ourself as the OnTouchListener.
this.setOnTouchListener(this);
}
public RegionView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
// Implement the Parent.
super(context, attrs, defStyleAttr);
// Initialize Member Variables.
this.mGestureDetector = new GestureDetector(context, this);
this.mViewMap = new HashMap<>();
this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
this.mScaling = false;
this.mWrapContent = false;
this.mDropOnScale = false;
// Register ourself as the OnTouchListener.
this.setOnTouchListener(this);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public RegionView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
// Implement the Parent.
super(context, attrs, defStyleAttr, defStyleRes);
// Initialize Member Variables.
this.mGestureDetector = new GestureDetector(context, this);
this.mViewMap = new HashMap<>();
this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
this.mScaling = false;
this.mWrapContent = false;
this.mDropOnScale = false;
// Register ourself as the OnTouchListener.
this.setOnTouchListener(this);
}
@Override
public boolean onTouch(final View v, final MotionEvent event) {
// Calculate the PointerId.
final int lPointerId = event.getPointerId(event.getActionIndex());
// Handle the TouchEvent.
this.getGestureDetector().onTouchEvent(event);
this.getScaleGestureDetector().onTouchEvent(event);
// Did the user release a pointer?
if(event.getAction() == MotionEvent.ACTION_UP) {
// Was there a View associated with this Action?
final View lView = this.getViewMap().get(lPointerId);
// Does the View exist?
if(lView != null) {
// Remove the View from the Map.
this.getViewMap().remove(lPointerId); /** TODO: Provide a Callback? */
}
}
// Consume all events for now.
return true;
}
@Override
public boolean onDown(MotionEvent e) {
// Calculate the PointerId.
final Integer lPointerId = Integer.valueOf(e.getPointerId(e.getActionIndex()));
// Fetch the View.
final View lView = this.getViewFor(Math.round(e.getRawX()), Math.round(e.getRawY()));
// Is it valid?
if(lView != null) {
// Watch the View.
this.getViewMap().put(lPointerId, lView);
// Configure the Anchor.
lView.setPivotX(0);
lView.setPivotY(0);
// Assert that we handled the event.
return true;
}
// Assert that we ignored the event.
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
// Are we not scaling?
if(!this.isScaling()) {
// Calculate the PointerId.
final Integer lPointerId = Integer.valueOf(e1.getPointerId(e1.getActionIndex()));
// Fetch the View.
final View lView = this.getViewMap().get(lPointerId);
// Is the scroll valid for a given View?
if(lView != null) {
// Calculate the Scaled Width and Height of the View.
final float lWidth = lView.getWidth() * lView.getScaleX();
final float lHeight = lView.getHeight() * lView.getScaleY();
// Declare the initial position.
final int[] lPosition = new int[] { (int)(e2.getX() - ((lWidth) / 2)), (int)(e2.getY() - ((lHeight) / 2)) };
// Are we wrapping content?
if(this.isWrapContent()) {
// Wrap the Position.
this.onWrapContent(lPosition, lWidth, lHeight);
}
// Update the Drag.
this.onUpdateDrag(lView, lPosition);
}
// Assert we handled the scroll.
return true;
}
// Otherwise, don't permit scrolling. Don't consume the MotionEvent.
return false;
}
/** Forces X/Y values to be coerced within the confines of the RegionView. */
private final void onWrapContent(final int[] pPosition, final float pWidth, final float pHeight) {
// Limit the parameters. (Top-Left)
pPosition[0] = Math.max(pPosition[0], 0);
pPosition[1] = Math.max(pPosition[1], 0);
// Limit the parameters. (Bottom-Right)
pPosition[0] = Math.min(pPosition[0], (int)(this.getWidth() - pWidth));
pPosition[1] = Math.min(pPosition[1], (int)(this.getHeight() - pHeight));
}
/** Updates the Drag Position of a child View within the Layout. Implicitly, we update the LayoutParams of the View. */
private final void onUpdateDrag(final View pView, final int pLeft, final int pTop) {
// Allocate some new MarginLayoutParams.
final MarginLayoutParams lMarginLayoutParams = new MarginLayoutParams(pView.getLayoutParams());
// Update the Margin.
lMarginLayoutParams.setMargins(pLeft, pTop, 0, 0);
// Refactor the MarginLayoutParams into equivalent LayoutParams for the RelativeLayout.
pView.setLayoutParams(new RelativeLayout.LayoutParams(lMarginLayoutParams));
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
// Calculate the ScaleFactor.
float lScaleFactor = detector.getScaleFactor() - 1;
// Fetch the Scaled View.
final View lView = this.getViewMap().entrySet().iterator().next().getValue();
// Update the ScaleFactor.
final float lScale = this.getScale() + lScaleFactor;
// Calculate the Proposed Width and Height.
final int lWidth = Math.round(lView.getWidth() * lScale);
final int lHeight = Math.round(lView.getHeight() * lScale);
// Is the View already too large for wrap content?
if(lWidth >= this.getWidth() || lHeight >= this.getHeight()) {
// Don't update the scale.
return false;
}
// Persist this Scale for the View.
lView.setScaleX(lScale);
lView.setScaleY(lScale);
// Assign the Scale.
this.setScale(lScale);
// Compute the Position.
final int[] lPosition = new int[] { Math.round(detector.getFocusX()) - (lWidth / 2), Math.round(detector.getFocusY()) - (lHeight / 2) };
// Are we wrapping the Position?
if(this.isWrapContent()) {
// Wrap the Position.
this.onWrapContent(lPosition, lWidth, lHeight);
}
// Update the Drag.
this.onUpdateDrag(lView, lPosition);
// Assert that we handled the scale.
return true;
}
/** Update the Drag. */
private final void onUpdateDrag(final View pView, final int[] pPosition) {
// Call the sub-implementation.
this.onUpdateDrag(pView, pPosition[0], pPosition[1]);
}
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// Is the user not dragging at all?
if(this.getViewMap().size() == 1) {
// Fetch the View.
final View lView = this.getViewMap().entrySet().iterator().next().getValue();
// Initialize the Scale.
this.setScale(lView.getScaleX());
// Assert that we've started scaling.
this.setScaling(true);
// Inform the callback.
return true;
}
// Otherwise, don't allow scaling.
return false;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
// Were we scaling?
if(this.isScaling()) {
// Assert that we've stopped scaling.
this.setScaling(false);
// Reset the Scale.
this.setScale(Float.NaN);
// Should we stop dragging now that we've finished scaling?
if(this.isDropOnScale()) {
// Clear the ViewMap.
this.getViewMap().clear();
}
}
}
/** Returns the View colliding with the given co-ordinates. */
private final View getViewFor(final int pX, final int pY) {
// Declare the LocationBuffer.
final int[] lLocationBuffer = new int[2];
// Iterate the Views.
for(int i = 0; i < this.getChildCount(); i++) {
// Fetch the child View.
final View lView = this.getChildAt(i);
// Fetch its absolute position.
lView.getLocationOnScreen(lLocationBuffer);
// Determine if the MotionEvent collides with the View.
if(pX > lLocationBuffer[0] && pY > lLocationBuffer[1] && (pX < lLocationBuffer[0] + (lView.getWidth() * lView.getScaleX())) && (pY < lLocationBuffer[1] + (lView.getHeight() * lView.getScaleY()))) {
// Return the View.
return lView;
}
}
// We couldn't find a View.
return null;
}
/* Unused Overrides. */
@Override public void onShowPress(MotionEvent e) { }
@Override public boolean onSingleTapUp(MotionEvent e) {
return false;
}
@Override public void onLongPress(MotionEvent e) { }
@Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { return false; }
/* Getters and Setters. */
private final GestureDetector getGestureDetector() {
return this.mGestureDetector;
}
private final ScaleGestureDetector getScaleGestureDetector() {
return this.mScaleGestureDetector;
}
private final Map<Integer, View> getViewMap() {
return this.mViewMap;
}
private final void setScaling(final boolean pIsScaling) {
this.mScaling = pIsScaling;
}
private final boolean isScaling() {
return this.mScaling;
}
private final void setScale(final float pScale) {
this.mScale = pScale;
}
private final float getScale() {
return this.mScale;
}
/** Defines whether we coerce the drag and zoom of child Views within the confines of the Layout. */
public final void setWrapContent(final boolean pIsWrapContent) {
this.mWrapContent = pIsWrapContent;
}
public final boolean isWrapContent() {
return this.mWrapContent;
}
/** Defines whether a drag operation is considered 'finished' once the user finishes scaling a view. */
public final void setDropOnScale(final boolean pIsDropOnScale) {
this.mDropOnScale = pIsDropOnScale;
}
public final boolean isDropOnScale() {
return this.mDropOnScale;
}
}
结果是01112（一个字符串）