PAT 甲級 1060 Are They Equal (25 分)(科學計數法,接連做了2天,考慮要全面,坑點多,真麻煩)...

1060 Are They Equal (25 分)

If a machine can save only 3 significant digits, the float numbers 12300 and 12358.9 are considered equal since they are both saved as 0 with simple chopping. Now given the number of significant digits on a machine and two float numbers, you are supposed to tell if they are treated equal in that machine.

Each input file contains one test case which gives three numbers N, A and B, where N (<) is the number of significant digits, and A and B are the two float numbers to be compared. Each float number is non-negative, no greater than 1, and that its total digit number is less than 100.

For each test case, print in a line <code>YES</code> if the two numbers are treated equal, and then the number in the standard form <code>0.d[1]...d[N]*10^k</code> (<code>d[1]</code>&gt;0 unless the number is 0); or <code>NO</code> if they are not treated equal, and then the two numbers in their standard form. All the terms must be separated by a space, with no extra space at the end of a line.

Note: Simple chopping is assumed without rounding.

題意：

給出兩個數，問：将他們寫成保留N (&lt;100)位小數的科學計數法 <code>0.d[1]...d[N]*10^k</code> (<code>d[1]</code>&gt;0 unless the number is 0); 後，是否相同。若相等，輸出YES，并轉換結果； 如果不相等，輸出NO，并給出兩個數的轉換結果。

題解:

本題的思路難想而且情況判斷非常複雜。

題目要求科學計數法時，兩個數是否相等。是以隻要判斷科學技術法時的本體部分以及指數部分是否相等即可。

對于資料來說，要分為大于 1 與小于 1 來判斷，要考慮各種情況下的數字，比如：0000， 000.00， 00123.4， 0.012, 0.00 等

一開始沒有考慮太多的異常情況，拿了19分，第二天看了題解的注意點重做，還是隻有21分，

第三天理了理思路，其實，隻要關注，格式化好後的小數點要點在哪裡，次數是多少就可以了，在此基礎上，特判0，去掉前導零。比較的時候注意不要超限，輸出不夠0補齊。

自己編的測試樣例：

AC代碼：