[luoguP2854] [USACO06DEC]牛的过山车Cow Roller Coaster（DP + sort）

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <iostream>
 4 #include <algorithm>
 5 
 6 int L, N, B;
 7 int f[10001][1001];
 8 
 9 inline int read()
10 {
11     int x = 0, f = 1;
12     char ch = getchar();
13     for(; !isdigit(ch); ch = getchar()) if(ch == ‘-‘) f = -1;
14     for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - ‘0‘;
15     return x * f;
16 }
17 
18 struct node
19 {
20     int x, w, f, c;
21 }p[10001];
22 
23 inline bool cmp(node x, node y)
24 {
25     return x.x < y.x;
26 }
27 
28 inline int max(int x, int y)
29 {
30     return x > y ? x : y;
31 }
32 
33 int main()
34 {
35     int i, j;
36     L = read();
37     N = read();
38     B = read();
39     for(i = 1; i <= N; i++)
40     {
41         p[i].x = read();
42         p[i].w = read();
43         p[i].f = read();
44         p[i].c = read();
45         p[i].w += p[i].x;
46     }
47     std::sort(p + 1, p + N + 1, cmp);
48     memset(f, -1, sizeof(f));
49     for(i = 0; i <= B; i++) f[0][i] = 0;
50     for(i = 1; i <= N; i++)
51         for(j = B; j >= p[i].c; j--)
52             if(f[p[i].x][j - p[i].c] ^ -1)
53                 f[p[i].w][j] = max(f[p[i].w][j], f[p[i].x][j - p[i].c] + p[i].f);
54     printf("%d\n", f[L][B]);
55     return 0;
56 }