洛谷P1303 A*B Problem

题目

求两数的积。

题解

高精度乘法

代码

var  n,i,j:longint;  s1,s2:ansistring;  a,b,c:array[1..100000]of longint;procedure mub;var  i,j,x:longint;begin  for i:=1 to length(s1) do    begin      x:=0;      for j:=1 to length(s2) do        begin          c[i+j-1]:=a[i]*b[j]+x+c[i+j-1];          x:=c[i+j-1] div 10;          c[i+j-1]:=c[i+j-1] mod 10;        end;      c[i+j]:=x;    end;end;begin  readln(s1);  readln(s2);  for i:=1 to length(s1) do    a[length(s1)-i+1]:=ord(s1[i])-ord('0');  for i:=1 to length(s2) do    b[length(s2)-i+1]:=ord(s2[i])-ord('0');  mub;  i:=100000;  while (c[i]=0)and(i>1) do dec(i);  for j:=i downto 1 do    write(c[j]);end.