高精度乘法

#include<bits/stdc++.h>
using namespace std;
char s1[2005],s2[2005];
int a[2005],b[2005],c[2005];
int main(){
	int la,lb,lc;
	scanf("%s",&s1);
	scanf("%s",&s2);
	la = strlen(s1);
	lb = strlen(s2);
	for(int i=0;i<la;i++) a[la-i] = s1[i] - '0';
	for(int i=0;i<lb;i++) b[lb-i] = s2[i] - '0';
	
	lc = la + lb;
	
	for(int i=1;i<=la;i++){
		for(int j=1;j<=lb;j++){
			c[i+j-1] = a[i]*b[j];
			c[i+j] += a[i]*b[j]/10;
			c[i+j-1] %= 10;
		}
	}
	
	if(c[lc] == 0 && lc > 0) lc--;
	for(int i=lc;i>0;i--) printf("%d",c[i]);
	
	
	return 0;
}