程序代码：

#include"iostream"
#include"string"
using namespace std;
int main()
{
    int t;
    cin >> t;
    while (t--)
    {
        int flag = 1;
        char a[1010], b[1010], c[1011];
        memset(a, '0', sizeof(a));
        memset(b, '0', sizeof(b));
        memset(c, '0', sizeof(c));
        cin >> a >> b;
        int l = (strlen(a) >= strlen(b)) ? strlen(a) : strlen(b);
        for (int l = strlen(a), i = 0; i < l/2; i++)
        {
            char t = a[i];
            a[i] = a[l - i - 1]-48;
            a[l - i - 1] = t-48;
        }
        for (int l = strlen(b), i = 0; i < l/2; i++)
        {
            char t = b[i];
            b[i] = b[l - i - 1]-48;
            b[l - i - 1] = t-48;
        }    
        for (int i = 0; i < l; i++)
        {
            c[i] = a[i] + b[i];
            for (int i = 0; i < l; i++)
            if (c[i] >= 10)
            {
                c[i] = c[i] % 10;
                c[i + 1] =c[i]+ 1;
            }
        }

    cout << "Case " << flag << ":" << endl;
    for (int i = strlen(a) - 1; i >= 0; i--)
    {
        a[i] += 48;
        if (a[i] == '0')
            continue;
        cout << a[i];
    }    
        cout << " + ";
        for (int i = strlen(b) - 1; i >= 0; i--)
        {
            b[i] += 48;
            if (b[i] == '0')
                continue;
            cout << b[i];
        }
        cout << " = ";
        for (int i = 1005; i >= 0; i--)
        {
            if (c[i] == '0')
                continue;
            c[i] += 48;
            cout << c[i];
        }
        cout << endl;
        flag++;
    }
}