UVa 10003 (可用四边形不等式优化) Cutting Sticks

 1 //#define LOCAL
 2 #include <iostream>
 3 #include <cstdio>
 4 #include <cstring> 
 5 using namespace std;
 6 
 7 const int INF = 1000000000;
 8 const int maxn = 60;
 9 int a[maxn], L, n, d[maxn][maxn];
10 
11 int main(void)
12 {
13     #ifdef LOCAL
14         freopen("10003in.txt", "r", stdin);
15     #endif
16 
17     while(scanf("%d", &L) == 1 && L)
18     {
19         scanf("%d", &n);
20         for(int i = 1; i <= n; ++i)    scanf("%d", &a[i]);
21         a[0] = 0, a[++n] = L;
22         //for(int i = 0; i < n; ++i)    d[i][i+1] = a[i+1] - a[i];
23 
24         for(int l = 2; l <= n; ++l)
25             for(int i = 0; i + l <= n; ++i)
26             {
27                 d[i][i+l] = INF;
28                 for(int k = i + 1; k < i + l; ++k)
29                     d[i][i+l] = min(d[i][k] + d[k][i+l] + a[i+l] - a[i], d[i][i+l]);
30             }
31         
32         printf("The minimum cutting is %d\n", d[0][n]);
33     }
34 
35     return 0;
36 }