7. 反转整数(Reverse Integer) C++

知识点：

• 内置变量 INT_MAX   INT_MIN
• 运算结果是否溢出的判断
  • 判断pop>7即pop>INT_MAX%10
  • 判断pop<-8即pop<INT_MIN%10

• class Solution {
  public:
      int reverse(int x) {
          int pop,ans=;
          while(x)
          {
              pop = x%;
              x /= ;
              if(ans > INT_MAX/ || (ans == INT_MAX/ && pop >))
                  return ;
              if(ans < INT_MIN/ || (ans == INT_MIN/ && pop <-))
                  return ;
              //cout << "pop: " << pop << " ans: " << ans << '\n';
              ans = ans* + pop;
          }
          return ans;
      }
  };