SPOJ Problem 54:Julka

#include<cstdio>
#include<cstring>
char x[105],y[105];
int a[105],b[105],c[105];
int l1,l2,i,j,s;
int main(){
    while(scanf("%s%s",&x,&y)!=EOF){
        memset(a,0,sizeof(a));
        memset(b,0,sizeof(b));
        l1=strlen(x);l2=strlen(y);
        for (i=0;i<l1;i++)
            a[l1-i]=x[i]-48;
        for (i=0;i<l2;i++)
            b[l2-i]=y[i]-48;
        for (i=1;i<=l1;i++){
            a[i]=a[i]+b[i]+a[i-1]/10;
            a[i-1]%=10;
        }
        s=0;
        for (i=l1;i;i--){
            a[i]+=s*10;
            s=a[i]&1;
            a[i]>>=1;
        }
        if (!a[l1])l1--;
        for (i=l1;i;i--)
            printf("%d",a[i]);
        printf("\n");
        for (i=1;i<=l1;i++){
            a[i]=a[i]-b[i];
            if (a[i]<0){a[i+1]--;a[i]+=10;}
        }
        while(!a[l1])l1--;
        for (i=l1;i;i--)
            printf("%d",a[i]);
        printf("\n");
    }
}