UVA 10106 Product （大数相乘）

来源：互联网发布：知乎盐水去甲醛编辑：程序博客网时间：2024/04/29 15:51

Product

The Problem

The problem is to multiply two integers X, Y. (0<=X,Y<10²⁵⁰)

The Input

The input will consist of a set of pairs of lines. Each line in pair contains one multiplyer.

The Output

For each input pair of lines the output line should consist one integer the product.

Sample Input

12122222222222222222222222222

Sample Output

144444444444444444444444444

大数相乘，网上有很多模板，今下午练练手，自己写一遍，刚开始忽略了前置0，导致0*12=00,0*123=000，后来改了输出就ac了。

#include <iostream>#include <cstring>#define maxn 260using namespace std;int main(){    char str1[maxn],str2[maxn];    while(cin>>str1>>str2){int len1,len2;len1=strlen(str1);len2=strlen(str2);int s1[maxn],s2[maxn];memset(s1,0,sizeof(s1));memset(s2,0,sizeof(s2));int i;for(i=0;i<len1;i++)s1[i]=str1[i]-'0';for(i=0;i<len2;i++)s2[i]=str2[i]-'0';int sum[maxn+maxn];memset(sum,0,sizeof(sum));int j,k;for(i=len2-1;i>=0;i--){for(j=len1-1;j>=0;j--){sum[i+j+1]=sum[i+j+1]+s2[i]*s1[j];}}for(k=len1+len2-1;k>=0;k--)if(sum[k]>=10){int temp;temp=sum[k]%10;sum[k-1]=sum[k-1]+sum[k]/10;sum[k]=temp;}//if(sum[0]!=0)//cout<<sum[0];bool flag=0;for(i=0;i<len1+len2-1;i++){if(sum[i]!=0)flag=1;if(flag==1)cout<<sum[i];}cout<<sum[len1+len2-1];cout<<endl;}    return 0;}

0 0