题目描述:求两个数相乘的值
套大数相乘模板即可
#include<stdio.h>
#include<string.h>
void mul(char a[],char b[])
{
int i,j,la,lb,lc;
int na[100]={0},nb[100]={0},nc[100]={0};
la = strlen(a);
lb = strlen(b);
//字符串转移到数组中 地位放前好计算
for(i = 0; i < la; i ++)
na[la-i] = a[i] - '0';
for(i = 0; i < lb; i ++)
nb[lb-i] = b[i] - '0';
//存储结果
for(i = 1; i <= la; i ++)
for(j = 1; j <= lb; j ++)
nc[i+j-1] += na[i]*nb[j];
//从低位向高位进位
for(i = 1; i <= la+lb; i ++)
{
nc[i+1] += nc[i]/10;
nc[i] %= 10;
}
if(nc[la+lb])//防止前导为0
printf("%d",nc[la+lb]);
for(i = la+lb-1; i >= 1; i --)
printf("%d",nc[i]);
}
int main()
{
char s1[100],s2[100];
while(scanf("%s %s",s1,s2) != EOF)
{
mul(s1,s2);
printf("\n");
}
return 0;
}