我的方法很简单，目前用到的就是两种：排除法、假设法。第一题只用排除法就能顺利完成。
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第一步：先看9个数字中，那个数字出现的次数多，9出现了6次，7出现了5次，就先从这两个数字开始。
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这样，表中所有的7和9就全部填进去了，以后就可以不用考虑这两个数字了。
第二步：看第1-3、4-6、7-9行或列有没有一个数字出现两次的，这样就能推断出来这3行或列里另外一个数字出现在哪里，比如第1、3列中都有2，那么不难得出，另一个2就在第2行、第2列相交的地方。我的习惯是先横后竖。
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这样，表中就填上了不少的数字了。
第三步：我的习惯是从左上角开始，会发现要同时满足存在且唯一，就能推断出所有的数字了。
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答案也就出来了。
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