Topics :  
multiplication of large numbers, we often meet a hundreds of-bit long number of multiplication between the programming problem, for example, in the algorithm, the ACM contest, the following is the large number of the detailed process of multiplication. 
Ideas
Analog Phase multiplication
To illustrate:
123*789=97047
Principle Show:
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/72/4F/wKioL1XgaqyQs0uGAAC3wmxUdzM008.jpg "title=" 2015-08-28_213104.png "alt=" Wkiol1xgaqyqs0ugaac3wmxudzm008.jpg "/>
Computer calculation:
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/72/4F/wKioL1XgatWBQ-jCAACepRjykuE963.jpg "title=" 2015-08-28_2133sa7.png "alt=" wkiol1xgatwbq-jcaaceprjykue963.jpg "/>,
C + + source code:
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/72/53/wKiom1XgaNOyWROnAAZZkdW_wPI314.jpg "title=" 2015-08-28_211829.png "alt=" Wkiom1xganoywronaazzkdw_wpi314.jpg "/>
Results show:
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/72/4F/wKioL1XgawDz6DfaAABQ2J-Rjlc731.jpg "title=" 2015-08-28_214129.png "alt=" wkiol1xgawdz6dfaaabq2j-rjlc731.jpg "/>650" this.width=650; "src=" http:// S3.51cto.com/wyfs02/m02/72/53/wkiom1xgapcddw_laad2tscwk7m267.jpg "title=" 2015-08-28_214208.png "alt=" Wkiom1xgapcddw_laad2tscwk7m267.jpg "/>
ACM Contest Topic "C + + large number multiplication"