借用arraystack的包完成

import "github.com/emirpasic/gods/stacks/arraystack"func isValid(s string) bool {stack := arraystack.New()for _, c := range s {if c == '(' {stack.Push(')')} else if c == '[' {stack.Push(']')} else if c == '{' {stack.Push('}')} else {if stack.Empty() {return false}tempC, _ := stack.Pop()if tempC != c {return false}}}return stack.Empty()
}

接下来分析一下arraystack的实现

arraystack

用法

A stack based on a array list.

ArrayStack
A stack based on a array list.Implements Stack, IteratorWithIndex, JSONSerializer and JSONDeserializer interfaces.package mainimport "github.com/emirpasic/gods/stacks/arraystack"func main() {stack := arraystack.New() // emptystack.Push(1)             // 1stack.Push(2)             // 1, 2stack.Values()            // 2, 1 (LIFO order)_, _ = stack.Peek()       // 2,true_, _ = stack.Pop()        // 2, true_, _ = stack.Pop()        // 1, true_, _ = stack.Pop()        // nil, false (nothing to pop)stack.Push(1)             // 1stack.Clear()             // emptystack.Empty()             // truestack.Size()              // 0
}

stack的new，push和pop

// Push adds a value onto the top of the stack
func (stack *Stack) Push(value interface{}) {stack.list.Add(value)
}// Pop removes top element on stack and returns it, or nil if stack is empty.
// Second return parameter is true, unless the stack was empty and there was nothing to pop.
func (stack *Stack) Pop() (value interface{}, ok bool) {value, ok = stack.list.Get(stack.list.Size() - 1)stack.list.Remove(stack.list.Size() - 1)return
}// String returns a string representation of container
func (stack *Stack) String() string {str := "ArrayStack\n"values := []string{}for _, value := range stack.list.Values() {values = append(values, fmt.Sprintf("%v", value))}str += strings.Join(values, ", ")return str
}

A stack based on a array list。

// Add appends a value at the end of the list
func (list *List) Add(values ...interface{}) {list.growBy(len(values))for _, value := range values {list.elements[list.size] = valuelist.size++}
}// Get returns the element at index.
// Second return parameter is true if index is within bounds of the array and array is not empty, otherwise false.
func (list *List) Get(index int) (interface{}, bool) {if !list.withinRange(index) {return nil, false}return list.elements[index], true
}// Remove removes the element at the given index from the list.
func (list *List) Remove(index int) {if !list.withinRange(index) {return}list.elements[index] = nil                                    // cleanup referencecopy(list.elements[index:], list.elements[index+1:list.size]) // shift to the left by one (slow operation, need ways to optimize this)list.size--list.shrink()
}

list

// Check that the index is within bounds of the list
func (list *List) withinRange(index int) bool {return index >= 0 && index < list.size
}func (list *List) resize(cap int) {newElements := make([]interface{}, cap, cap)copy(newElements, list.elements)list.elements = newElements
}// Expand the array if necessary, i.e. capacity will be reached if we add n elements
func (list *List) growBy(n int) {// When capacity is reached, grow by a factor of growthFactor and add number of elementscurrentCapacity := cap(list.elements)if list.size+n >= currentCapacity {newCapacity := int(growthFactor * float32(currentCapacity+n))list.resize(newCapacity)}
}