HDUOJ 1002: A + B Problem II

#include <iostream>
#include <memory.h>
#include <cstring>
using namespace std;

int main()
{
    char a[1000], b[1000], s[1001];
    int t;
    cin >> t;
    int ct = 1;
    while(t--)
    {
        cin >> a >> b;
        int lena = strlen(a) - 1;
        int lenb = strlen(b) - 1;
        int j, p = 0;
        for(j = 0; lena >= 0 || lenb >= 0; ++j, --lena, --lenb)
        {
            if(lena >= 0 && lenb >= 0) s[j] = a[lena] + b[lenb] - '0' + p;
            if(lena >= 0 && lenb < 0) s[j] = a[lena] + p;
            if(lena < 0 && lenb >= 0) s[j] = b[lenb] + p;
            p = 0;
            if(s[j] - '0' > 9)
            {
                s[j] -= 10;
                p = 1;
            }
        }
        cout << "Case " << ct++ << ":\n";
        cout << a << " + " << b << " = ";
        if(p) cout << 1;
        for(--j; j >= 0; --j)
            cout << s[j];
        cout << endl;
        if(0 != t) cout << endl;
    }
    return 0;
}