题解 | #逆波兰表达式求值#

package main
import "fmt"
import "strconv"

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param tokens string字符串一维数组 
 * @return int整型
*/
func evalRPN( tokens []string ) int {
    // write code here
    stack := make([]int,0);
    for i:=0;i<=len(tokens)-1;i++{
        switch {
            case tokens[i]=="+": 
            b := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			a := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			stack = append(stack, a+b) 
            case tokens[i]=="*": 
            b := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			a := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			stack = append(stack, a*b) 
            case tokens[i]=="-": 
            b := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			a := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			stack = append(stack, a-b)   
            case tokens[i]=="/": 
            b := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			a := stack[len(stack)-1]  
			stack = stack[:len(stack)-1]  
			stack = append(stack, a/b)    
            default :
            num,err := strconv.Atoi(tokens[i]);
            if err!= nil{
                   fmt.Printf("转换失败");
            }
            stack=append(stack, num);
        }
    }
    return stack[0];
}