HDU 5119 背包

题意：告诉n个数字，在其中选择0~n个数字，异或，然后求得到的结果不小于m的个数。

分析：超了int，本来说的是枚举，后来大姐头自己变成了背包DP。牛牪犇！！！

 1 #include <cstdio>
 2 #include <iostream>
 3 #include <sstream>
 4 #include <cmath>
 5 #include <cstring>
 6 #include <cstdlib>
 7 #include <string>
 8 #include <vector>
 9 #include <map>
10 #include <set>
11 #include <queue>
12 #include <stack>
13 #include <algorithm>
14 using namespace std;
15 #define ll long long
16 #define _cle(m, a) memset(m, a, sizeof(m))
17 #define repu(i, a, b) for(int i = a; i < b; i++)
18 #define repd(i, a, b) for(int i = b; i >= a; i--)
19 #define sfi(n) scanf("%d", &n)
20 #define pfi(n) printf("%d\n", n)
21 #define N 1000010
22 #define M 25
23 ll dp[N][2];
24 int main()
25 {
26     int T;
27     sfi(T);
28     repu(kase, 1, T + 1)
29     {
30         _cle(dp, 0);
31         int n, m;
32         sfi(n), sfi(m);
33         int x;
34         int flag = 0;
35         int maxn = 0;
36         dp[0][1] = 1;
37         repu(i, 0, n)
38         {
39             sfi(x);
40             int tmaxn = maxn;
41             repu(j, 0, maxn + 1)
42             dp[j][flag] = dp[j][!flag];
43             repu(j, 0, maxn + 1)
44             {
45                 int t = x ^ j;
46                 dp[t][flag] += dp[j][!flag];
47                 tmaxn = max(t, tmaxn);
48             }
49             maxn = tmaxn;
50             flag = !flag;
51         }
52         ll sum = 0;
53         repu(i, m, maxn + 1)
54         {
55             sum += dp[i][!flag];
56         }
57         printf("Case #%d: %I64d\n", kase, sum);
58     }
59     return 0;
60 }
对DP比较恐惧，屯个代码

 

posted @ 2015-08-31 20:28  一麻袋码的玛侬  阅读(99)  评论(0)  编辑  收藏  举报