POJ 2718 Smallest Difference

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <map>
 4 #include <vector>
 5 #include <functional>
 6 #include <string>
 7 #include <cstring>
 8 #include <queue>
 9 #include <set>
10 #include <cmath>
11 #include <cstdio>
12 using namespace std;
13 #define IOS ios_base::sync_with_stdio(false)
14 #define TIE std::cin.tie(0)
15 #define MIN2(a,b) (a<b?a:b)
16 #define MIN3(a,b) (a<b?(a<c?a:c):(b<c?b:c))
17 #define MAX2(a,b) (a>b?a:b)
18 #define MAX3(a,b,c)  (a>b?(a>c?a:c):(b>c?b:c))
19 typedef long long LL;
20 typedef unsigned long long ULL;
21 const int INF = 0x3f3f3f3f;
22 const double PI = 4.0*atan(1.0);
23 
24 int ca, n, a[15], ans, m1, m2, x;
25 int Input()
26 {
27     int n = 0;
28     char ch=‘ ‘;
29     while (ch!=‘\n‘){
30         if (‘0‘ <= ch&&ch <= ‘9‘){
31             a[n++] = ch - ‘0‘;
32         }
33         ch = getchar();
34     }
35     return n;
36 }
37 int main()
38 {
39     scanf("%d", &ca);
40     getchar();
41     while (ca--){
42         n = Input();
43         sort(a, a + n);
44         ans = INF;
45         do{
46             if (a[0] == 0 || a[n / 2] == 0 && n>2) continue;
47             m1 = m2 = 0;
48             for (int i = 0; i < n / 2; i++){
49                 m1 *= 10;  m1 += a[i];
50             }
51             for (int i = n / 2; i < n; i++){
52                 m2 *= 10;  m2 += a[i];
53             }
54             x = abs(m1 - m2);
55             if (x < ans) ans = x;
56         } while (next_permutation(a, a + n));
57         printf("%d\n", ans);
58     }
59 }