一道C语言面试题——大数相乘的问题

来源：互联网发布：淘宝号冻结了怎么解冻编辑：程序博客网时间：2024/05/10 02:56

#include "stdafx.h"

void Multiple(char A[], char B[], char C[])
{
    int TMP, In=0, LenA=-1, LenB=-1;
    while(A[++LenA] != '/0');
    while(B[++LenB] != '/0');
    int Index, Start = LenA + LenB - 1;
    for(int i=LenB-1; i>=0; i--)
    {
        Index = Start--;
        if(B[i] != '0')
        {
            for(int In=0, j=LenA-1; j>=0; j--)
            {
                TMP = (C[Index] - '0') + (A[j] - '0') * (B[i] - '0') + In;
                C[Index--] = TMP % 10 + '0';
                In = TMP / 10;
            }
            C[Index] = In + '0';
        }
    }
}

int main(int argc, char* argv[])
{
    char A[] = "218392444444444444888888888800088888889";
    char B[] = "388888888888999999999999945669999999988";
    char C[sizeof(A) + sizeof(B) - 1];

    for(int k=0; k<sizeof(C); k++)
        C[k] = '0';
    C[sizeof(C)-1] = '/0';

    Multiple(A, B, C);
    for(int i=0; C[i] != '/0'; i++)
        printf("%c", C[i]);
    return getchar();
}