题解 | #逆波兰表达式求值#
逆波兰表达式求值
https://www.nowcoder.com/practice/885c1db3e39040cbae5cdf59fb0e9382
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]; }