3116 高精度练习之加法

#include<cstdio>
#include<iostream>
#include<cstring>
#define ref(i,x,y)for(int i=x;i<=y;i++)
#define def(i,x,y)for(int i=x;i>=y;i--)
using namespace std;
int lena,lenb,lenc,a[1010],b[1010],c[1010];
char a1[1010],b1[1010];
int main()
{
    scanf("%s%s",a1,b1);
    lena=strlen(a1);lenb=strlen(b1);
    lenc=max(lena,lenb);
    ref(i,0,lena-1) a[lena-i]=a1[i]-48;
    ref(i,0,lenb-1) b[lenb-i]=b1[i]-48;
    ref(i,1,lenc){
        c[i]+=a[i]+b[i];
        c[i+1]+=c[i]/10;
        c[i]%=10;
    }
    int j=lenc+1;
    while(c[j]==0&&j>1) j--;
    def(i,j,1) printf("%d",c[i]);
    return 0;
}