HDOJ 1402 A * B Problem Plus -- FFT

A * B Problem Plus

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 11652 Accepted Submission(s): 2005

[align=left]Problem Description[/align]
Calculate A * B.

Input
Each line will contain two integers A and B. Process to end of file.

Note: the length of each integer will not exceed 50000.

[align=left]Output[/align]
For each case, output A * B in one line.

[align=left]Sample Input[/align]

1
2
1000
2

[align=left]Sample Output[/align]

2
2000

分析：FFT模板。