3754. 连接非零数字并乘以其数字和 I

https://leetcode.cn/problems/concatenate-non-zero-digits-and-multiply-by-sum-i/description/?envType=daily-question&envId=2026-07-06

比较简单，直接做

function sumAndMultiply(n: number): number {
      // 转成字符串，遍历去掉 0
      const str = String(n)

      // 相加
      let sum = 0
      let x = ""
      for(let i = 0; i < str.length ;i++){
        if(str[i]!=="0"){
          sum += Number(str[i])
          x += str[i]
        }
      }

      return sum * Number(x)
  };