LeetCode #246 - Strobogrammatic Number

最新推荐文章于 2023-12-19 15:37:43 发布

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本文介绍了一种算法，用于判断一个数字是否为旋转对称数，即该数字在旋转180度后仍然保持不变。通过使用C++实现的函数isStrobogrammatic，文章详细解析了如何比较数字字符串两端的字符，确保它们在旋转后的对应性。

题目描述：

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).

Write a function to determine if a number is strobogrammatic. The number is represented as a string.

Example 1:

Input: "69"

Output: true

Example 2:

Input: "88"

Output: true

Example 3:

Input: "962"

Output: false

class Solution {
public:
    bool isStrobogrammatic(string num) {
        int i=0;
        int j=num.size()-1;
        while(i<=j)
        {
            if(i==j&&(num[i]=='1'||num[i]=='0'||num[i]=='8')) return true;
            if((num[i]=='1'&&num[j]=='1')||(num[i]=='0'&&num[j]=='0')||(num[i]=='8'&&num[j]=='8')||
               (num[i]=='6'&&num[j]=='9')||(num[i]=='9'&&num[j]=='6'))
            {
                i++;
                j--;
            }
            else return false;
        }
        return true;
    }
};