问题
I am attempting to reverse an array using a stack. However, I get an error on arr[i] = stack.top();, and the suggestion to resolve it in Eclipse is to change it to arr[i] = stack.pop(); or to add a cast. Is there another way about this or have I made a mistake?
I see tutorials and questions asking about how to reverse a string using a stack and I have tried to reverse an array using the same logic, but I'm not entirely sure where I'm going wrong.
public static void reverse(String[] arr){
Stack stack = new Stack();
for(int i = 0; i < arr.length; i++) {
stack.push(arr[i]);
}
for(int i = 0; i < arr.length; i++) {
arr[i] = stack.top();
stack.pop();
}
return;
}
回答1:
When you pop the stack, it returns the object at the top and removes it from the stack. Try this:
public static void reverse(String[] arr){
Stack stack = new Stack();
for(int i = 0; i < arr.length; i++) {
stack.push(arr[i]);
}
for(int i = 0; i <arr.length;i++) {
arr[i] = stack.pop();
}
}
回答2:
Method top doesn't exist in the Stack of Java. The similar method you're looking for is peek. Take a look at http://docs.oracle.com/javase/7/docs/api/java/util/Stack.html
However, you can use only pop, because it returns the removed object.
来源：https://stackoverflow.com/questions/28268945/reversing-an-array-using-a-stack