luogu 2142 高精度减法

 1 #include <iostream>
 2 #include <string>
 3 #include <cstring>
 4 using namespace std;
 5 int main()
 6 {
 7     string a,b,tmp;
 8     int x[11000] = {},y[11000] = {},z[11000] = {};
 9     int ok = 0;
10     cin >> a >> b;
11     if ((a.length() < b.length()) || ((a.length() == b.length()) && a < b))
12     {
13         tmp = a;
14         a = b;
15         b = tmp;
16         ok = 1;
17     }
18     for (int i = 0;i < a.length();i++)
19         x[a.length() - i] = a[i] - '0';
20     for (int i = 0;i < b.length();i++)
21         y[b.length() - i] = b[i] - '0';
22     int len = 1;
23     while (len <= a.length() || len <= b.length())
24     {
25         if (x[len] < y[len])
26         {
27             x[len] = x[len] + 10;
28             x[len + 1] = x[len + 1] - 1; 
29         }
30         z[len] = x[len] - y[len];
31         len++;
32     }
33     while (z[len] == 0 && len >= 1)
34         len--;
35     if (len == 0)
36         len = 1; 
37     if (ok == 1)
38         cout << "-";
39     for (int i = len;i >= 1;i--)
40         cout << z[i];
41     return 0;
42 }
心之所动且就随缘去吧