题解 | LRU Cache

package main

import (
	"container/list"
	"fmt"
)
type Solution struct {
    Cap int
    Dict map[int] *list.Element
    MyList *list.List
}
type Pair struct {
    key,value int
}

func Construct(capacity int) Solution{
    return Solution{
        capacity, 
        map[int] *list.Element{},
        list.New(),
    }
}

func (this * Solution) get(key int) int {
    if res, ok := this.Dict[key]; ok {
        this.MyList.MoveToFront(res)
        return res.Value.(Pair).value
    } else {
        return -1
    }
}
func (this * Solution) set(key, value int) {
    //判断在不在缓存
    if res, ok := this.Dict[key]; ok {
        res.Value = Pair{key,value}
        // this.MyList.MoveToFront(res)
        // this.MyList.MoveToFront(res)
        return 
    } 
    this.Dict[key] = this.MyList.PushFront(Pair{key,value})
    if len(this.Dict) > this.Cap {
        res := this.MyList.Remove(this.MyList.Back())
        delete(this.Dict, res.(Pair).key)
    }
}

func main() {
    var cap int
    fmt.Scan(&cap)
    solution := Construct(cap)
    for {
        var op string
        // fmt.Println(op)
        _, err := fmt.Scan(&op)
        // fmt.Println(op, err)
        if err != nil {
            break
        }
        var key, value int
        if op == "p" {
            fmt.Scan(&key, &value)
            solution.set(key, value)
        } else if op == "g"{
            fmt.Scan(&key)
            res := solution.get(key)
            fmt.Println(res)
        }
        // fmt.Println(op, key, value)
    }

}