70pts:没输出no answer
40pts:操作数优先输出大的。放一段代码供参考:
if (a[1] < a[2])
swap(a[1], a[2]);
cout << a[1] << op[i] << a[2] << '=' << r[1] << '\n';
if (r[1] < a[3])
swap(r[1], a[3]);
cout << r[1] << op[j] << a[3] << '=' << r[2] << '\n';
if (r[2] < a[4])
swap(r[2], a[4]);
cout << r[2] << op[k] << a[4] << '=' << 24;
10pts:40pts的错误+70pts的错误